The LS3/5a – a midrange to die for Part II

In part II of the LS3/5a essay I will share some thoughts about choosing the right amplifier as also illuminate some of the specific construction details.

The KEF T50 tweeter

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Looking at the tweeter of a LS3/5a is somewhat strange….after we fought with the velcro fixed Tygan grill of the speaker we will see a strange looking (tea strainer) cover and there is no tweeter visible. But beliefe me – it is there….;-))) First lets talk about the grills….the frequency response of the LS3/5a is measured and constructed with the grills in place – so it is NOT recommended to get rid of them – as the speaker construction behind the grilles is everything else than beautiful it is also a good fashion statement to let the grills where they belong. The same has to be said about the tweeter cover….I once I read in an internet article, that it is necessary to get rid of them to achieve more treble energy – the opposite is true…. The vented covers raise the sensitivity of the tweeter instead of dampening the latter!!!! The KEF T50 is made out of Mylar foil……it is the same material chosen by the microphone manufacturers for their capsule membrane and…..yes – it is the same material our beloved Quad “membranes” are made of. It was not so common at the end of the 60ties (last century) to use synthetic materials for speaker development – so KEF stood out as one of the first manufacturers who thought about new materials. The T50 was nearly 10 years a sort of reference in its segment – a lot of different speaker designs were made around this legendary tweeter. This little gem is able to reproduce frequencies above 40Khz – something which is also not too common in our modern days. With the implementation of the LS3/5a dividing network the speaker features a slight raise toward the highest treble. It is the opposite of what we will find with the Quad ESL 57 which has a frequency roll off starting at 15 Khz which takes care of a slightly rolled off highest treble performance. The LS3/5a renders the treble in a completely different way. If we enjoy to use moving coil carts with a slight emphasis in the region of 15 – 20Khz (high frequency rise typical for most moving coils) with the Quad ESL 57, we will be more satisfied using the LS3/5a with cartridges which domesticate such behaviour. In other words – a top notch Lyra, like the Etna SL is a dream to use together with the Quad ESL 57, in contrast to that the LS3/5a loves cartridges like the Koetsu Urushi Wajima for example. As we are now aware of this special character of the LS3/5a in the treble department – we must avoid any gear – be it an amplifier, preamplifier or source component which has a somewhat tilted up treble performance….

The T50 is surrounded by a thick felt square which prevents the sound waves to become diffracted at the enclosure and the surface of the speaker. That is important as we already discussed in part I of this essay the tremendous omnidirectionality the LS3/5a has to offer.

The tweeter is electrically secured by a resistor in front of the latter (15 Ohm model) – this thing can get really, really hot – and sometimes – if you disassemble a LS3/5a, you will see some burnt damping foam around the position of this resistor. It can happen that those things are burnt – if you are lucky, it is just the resistor and not the whole tweeter…. A blown tweeter will resulting in buying two new (old) ones, because those tweeters were matched as a pair. And if you buy two new ones it is a good idea to measure their resistance (of the functioning one) because as you can read in part I – different tweeters (electrically) could be used with different tabs of the autoformers…..so you have to search for a replacement pair which fits the technical specs of that particular pair originally used in your specific speaker to get the same treble response once adjusted at the crossover board.

The KEF B110 woofer

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The B110 is a legend – it was one of the first speaker chassis made completely with a high damped synthetic material. KEF was searching for a lightweight as also robust material with a very good inner damping. They designed a completely new material to achieve that – and called it Bextrene! The very first B110 chassis had a membrane surrounding made of neoprene – later KEF opted for a rubber surrounding which was more consistent and easier to manufacture. If you look at the B110 woofer of any original LS3/5a, you will observe that it is mounted from the backside, which is totally uncommon in speaker design. If we want to achieve a time aligned behaviour of both speaker systems we would opt normally for the opposite, than mounting the bass chassis behind the plane of the tweeter. The LS3/5a crossover addressed that specific mounting position so that we will hear an astonishing phase coherency between the two speaker systems. In fact the crossover point is located around 3Khz so it is chosen in a very critical frequency region were our ear is very, very sensitive (Fletcher / Munson curve), but we will not detect any phase anomalies while listening to a proper installed LS3/5a. The B110 is a long throw woofer system to compensate for its small surface and size. Do not be afraid if you once observe the woofer moving while you are listening to some deep and strong bass impulses – what you see is normal;-))))…..If you overdo it, you will hear a loud Pock Pock sound, which is the voice coil former that knocks at the inner side of the magnet….so it is time to decrease your listening level.

The B110 gives us in the LS3/5a an amazing midrange performance – you can characterise the LS3/5a as a full range speaker with a tweeter on top….The whole important midrange spectrum is covered only by the B110! The woofers are also matched as a pair in our beloved mini monitor – so if one is defective – you are in for a very, very long search! If your B110 looks dirty – please be advised that it is not a good idea to use any liquid to clean the damn thing. Bextrene reacts not too good if it is mated with windex cleaner or pure water…so let the thing like it is – get rid of the dust and thats it!

The listening height should be adjusted so that your ear is located virtually between the tweeter and woofer position – if you sit too low, you might detect some strange phase anomalies, if the position is to high, the sensational imaging abilities would suffer seriously.

The Crossover

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As I explained in part I – every manufacturer of the 15 Ohm Ls3/5a made its own crossover. Most of the very early models used autoformers which were wound in house by the specific manufacturer. Later on the British company Drake delivered all licensees with their autoformer model leaving out Spendor – they used their own stuff till the 15 Ohm era was at its end. All LS3/5a crossovers share a distinct complexity. If you are a proper High End freak – and peek inside of such a dividing network – most of us would say – that cannot work – nor will it sound good….but the reality shows us every time we listen to these little speakers, that the BBC did an amazing job – the LS3/5a is one if the most important speaker designs of all time – and this is not my humble opinion only….

The parts of the finest LS3/5a 15 Ohm incarnations used throughout the circuit were top class in those years…..do not mess with them! I know that it is easy to find monster High End foil capacitors in the audio accessory shops today – but I can assure you – every moded version does loose its magic – and at the end you have destroyed an original! Let the things like they are – watch out for strongly used parts and try to replace them with the same type once used in your speaker (one of the reasons why in the strong far east scene they collect also parts of the LS3/5a…..). If you disassemble a LS3/5a you will aware of how complicated the whole thing was built. If you change the order of some washers or forget some of the rubber O rings, the little diva will not be air tight anymore….

Everything which is present and mounted in a certain way is not an option, it is very, very important – there is no place for tuning work or trying to better the performance other than using a better position in your room or better equipment to drive the little diva.

The amplifier

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The classic LS3/5a has an impedance of 15 Ohm which is totally unusual today. The maximum power these speakers will handle is around 25 – 30 stable watt. If we buy a little transistor amplifier which is able to produce 50 watt at 8 Ohm – the same amp will deliver 25 watt at 15 Ohm…keep that in mind. A transistor amp which works near its clipping is the best way to destroy any speaker – so you have to search for something a little bit beefier than 50 watt….the impedance figure of the LS3/5a is not so much loved by transistor electronic.

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The opposite is the case if we discuss 15 Ohm impedance together with a tube amplifier. Our tube amp might have output transformer taps which are made for 16 Ohm…. To understand the advantage of a high impedance speaker mated with a tube amp I have to explain things a little bit more. The outputstage of our tube amp has naturally a high impedance, it varies a little bit from tube type to tube type – but generally it is a high impedance figure. The output transformer is used to adjust for the high tube output impedance to be matched to the low speaker impedance. If we use a 4 Ohm speaker a lot more windings are necessary to achieve that as with a high impedance speaker, as the LS3/5a is. Finally a high impedance speaker design is a very good match for any given tube amplifier as also OTL (output transformerless) designs!

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As the LS3/5a is not very sensitive, you might think it is not a good idea to pair the speakers with low powered tube amps – but the opposite is true. The high impedance of the speaker compensates for its restricted sensitivity! A LS3/5a is not a good match for a SET amp like a 300B or even more so a 2A3 – both have too little power to drive the speaker to sufficient sound pressure levels, but a 6L6 GC push pull design or an EL 34 amplifier – may it configured in triode mode or as a penthode works like a charm. Keep in mind the little box is very, very accurate to the source – so if you think of something cheap and mediocre – the whole system will sound accordingly….If you opt for a transistor amplifier there are also great models out there which have a legendary status. The Naim chrome bumper amp range comes to mind or legendary class a amps from Britain (Sugden, Musical Fidelity A 1000) or the US (ML or Cello) as also the amazing Lavardin of our days. The latter is one of the most musical transistor amps that can drive a LS3/5a! But if we have the chance to listen to one of the rare 15 Ohm specimen today I would opt for a nice tube amp!

A tube advice

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With a tube amplifier we have the possibility to voice the amp to our liking – and if we listen to a LS3/5a using tube electronics it is time to praise the legendary Mullard MC1 ECC83. This is one of the oldest European ECC83 type of tubes and it sounds so damn fantastic with the legendary British speakers, if I did not know it better, I would guess they were constructed for each other. The Mullard MC1 features the one of a kind wrinkled glass surface as it also has a square getter construction and long narrow grey plates. To spot an original MC 1 we have to observe the lower segment of the tube – we will find there an etched code with the type MC1 and a number which should start with a capital B for the Blackburn production plant. The MC1 is not the only long plates Mullard ECC83 – the successor was named F92 and has also an amazing sound. To mate the Mullard MC1 with the proper ECC82 Mullard (phase inverter / preamplifier) things get a little bit exotic. The holy grail of all Mullard ECC82 is the military version of their ECC82 called CV 491 – and this is it….A Mullard CV 491 Long Plate together with its stablemate the MC1 is truly amazing. These tubes have a one of a kind bass gestalt. Full and tight as also very, very colourful – the dynamic abilities of the deepest octaves are astonishing. The midrange is reference class with a slight emphasis in the lower midband – which brings vocals in their three dimensional gestalt right in front of our speakers. The presence is somewhat defensive and opens up nicely towards the treble and air – I would call that a classic tube sound. The stage a Mullard is able to render is big and bolt – in this parameter it is one of the best tubes I know. I use them both in My Air Tight ATC2 HQ preamplifier together with a GEC CV 4005 rectifier and this preamp drives the ATM4 which I already described in my essay about the 6L6 GC – both amplifiers are mated with two Chartwell I and the performance is stunning!

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Keep in mind that all the old long plates Mullard sound completely different than the short plates incarnation made from 1960 onwards. The short plates – especially the I63 type is very smooth and even rolled off in the treble department which cannot be said about the long plates Mullard tubes of the ECC83 and ECC82 family. The downside of choosing these legendary British made signal tubes is their rarity and the high prices we have to pay today. But think about it in a different way….if you spent €600,- on a power cable or a signal cable the benefit would be much, much smaller as if you opt for such an outstanding electron tube!!!! These legendary Mullard long plates types are unmatched till today – no modern construction comes even close!

Quad ESL 57 versus LS3/5a

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If you like the sound of a Quad ESL 57 but you cannot place it in your room – than the LS3/5a is the closest thing to the original Quad in existence. It does not sound the same (of course not) – but the most important aspects of the reproduced music is cut from the same cloth. The LS3/5a can reproduce deeper frequencies with more impact if we position them in front of the long wall of our listening room (reed part 1 of this essay), the Quad on the other hand delivers its deepest frequencies with more accuracy and authority. Both are very, very fast reacting speaker systems, but the Quad is able to reproduce the leading edge in a fashion no other speaker can muster (unless we use also a ribbon or electrostatic construction). The LS3/5a can beam the sound into the room with an amazing omnidirectionality while the Quad is very much restricted in this discipline. If you want to listen to your favourite music with your family or friends and not alone, the LS3/5a is the better option, because you can enjoy their beautiful  performance also if you are not located near the sweet spot. Both speakers are able to deliver an astonishing resolution – but they do it in a different way. The LS3/5a is able to reproduce the treble and air section of the reproduced music in a nearly unlimited style, the Quads do not have that outstanding treble performance, instead of that, they are able to deliver the smallest shades of colour as also a tremendous amount of micro dynamic variations without having such an unlimited high frequency performance. Some people opt for a super tweeter in conjunction with the ESL 57 to get exactly that kind of “unlimited” treble performance – but till now I am not aware of any solution which does not destroy the tremendous rightness this speaker has to offer.

The LS3/5a can play a little bit louder than the original Quad ESL but we cannot speak about a real grown performance showing macro dynamic shades – far from that. That brings us to the biggest disadvantage both speaker systems share….the maximum sound pressure level and the rendering of really big dynamic swings. Both speakers will deliver an undistorted signal up to 100 – 104db  (in 1m) – and both are rather insensitive – the figures are nearly equal. If you can live with this restriction you will be payed off by so many seldom found qualities in the whole speaker market today, that it is my strongest advice to listen to one of them – maybe it will be your last pair of speakers……

Both constructions do not change their frequency coherence while played with varying volumes – so you are able to enjoy your favourite music in some intimate nighttime listening session in its full glory. If you are a mixing or mastering engineer this characteristic is highly appreciated and seldom found in any speaker design. The Quad shows even a miraculous feature, because it does not change its loudness proportional (logarithmic function) to the various listening distances – which I never detected with any other speaker system. What makes both constructions very special is the ability to get the complete midrange right. The Quad is in this regard a little bit more unforgiving, If there is any colouration in this frequency section present the electrostatic speakers will show you that in such a clear distinction, that you are amazed and sometimes shocked. Both speaker systems are able to render a soundstage you never will forget, the LS3/5a does that in a more bolt fashion, while the Quad has a more analytical gestalt with a tremendous pin point accuracy. The LS3/5a might be a little more spectacular if you do not listen carefully – maybe that is also achieved by the crazy discrepancy between the acoustic performance and the physical size of the little box.

To mate a LS3/5a with a sub woofer is not a good idea – I never heared till today any implementation of a separate woofer which  lets the masterful voicing of the little gem intact. No sub can react in such a fast way as the little Bextrene B100 chassis can do – so you get heavy phase anomalies in the upper bass – which will destroy a good portion of what a LS3/5a is all about.

Happy listening

 

E. Strauss

 

The LS3/5a – a midrange to die for Part I

I will not repeatedly report all about the history of this legendary BBC monitor again, there is nearly all information about the historical aspect scattered on the internet. My intention is to write about the different  models and incarnations of them, the amplifiers (may it tube or transistor) to drive these little shoeboxes, as also about the very important room placement which implies also some explanation of their construction.

The early period

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If you talk to LS3/5a devotees, you will always educated about the two most outstanding models, namely the Rogers Gold Tag 15 Ohm and the Chartwell I (also15 Ohm)….why is that? Both models are almost the oldest of the whole breed, and both are nearly vanished from the used market – and if you will find one, there is a good chance, that it is not anymore in its original condition, as also very, very expensive.

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There are some facts about the oldest versions of the LS3/5a and their different licensees, namely Rogers, Chartwell and also Audiomaster, which were all together in the forefront of building the BBC mini monitor, that has to be told. In the beginning of the 70ties (last century) all the licensees had to build their own crossover circuit – everything was done to meet the exact BBC specs, but the way it was done was into the responsibility of the different manufactures. So Rogers and Chartwell wound their specific autoformers in house during this period, and they both opted for different parts be it the foil capactitors used  or the brand of the different resistors needed – and even in the layout there were slight differences to be detected. Both used the same chassis delivered from the British manufacturer KEF, the legendary first version of the T50 tweeter identifiable because of the blue and black colour of the connection wires, as also the first version of the B110 woofer. But the implementation was rather different – both came out with a construction precisely matching the BBC specs – but both speakers sound a little bit different. The Rogers Gold Tag might have the warmest bass response of all LS3/5a, as also a magic midrange which is able to render the most three dimensional stage. The Chartwell in comparison had a tight bass response with a delicious rendered treble and higher presence  which is sooo smooth, that you would not detect at first the analytical abilities this model has to offer. The Chartwell is more about the monitor utilization in a control room were the Rogers is perfect for casual listening. Both have a tremendous smoothness in their presence and treble rendering as also the amazing ability to get the midrange right. It is an unforgettable experience to listen to a well recorded vocal trough this mini monitor speakers.

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As KEF always had problems to produce the chassis, be it the B110 woofer or the T50 tweeter, without the slightest variation, all models share a circuit in their crossover, were the bespoke autoformer offered 4 taps to accommodate for variations of the speaker chassis delivered by KEF. One LS3/5a manufacturer stood out, which was Spendor. They opted against such a solution, instead they did the most rigorous selection of the delivered speaker chassis, and used only those, which were compatible with the specs of their crossover. This is maybe the reason for the phenomenal openness this first Spendor Gold Tag 15 Ohm model distinguished itself. It is maybe the most precisious and uncoloured treble performance of all LS3/5a ever built.

All those early models share the same sensitivity of around 83db/1W/1m and they all have nearly the same frequency response (with just very tiny variations) as also the same electrical parameters – but they all differ in their dynamic and micro dynamic abilities – something the BBC had not standardized too much.

The second period

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After the first years a lot of things changed in the history of the LS3/5a – Chartwell broke and was bought up by Rogers which delivered now LS3/5a speakers with a Chartwell Logo as a sort of high end version of the monitor, which was not really profitable, so that they stopped it after the different parts and pre manufactured crossovers (still made by Chartwell) were depleted. These so called Chartwell II is somewhat a mixture of the Rogers White Tag brought out by the latter using their own parts, and an original Chartwell – all of the Chartwell II versions differ in small details may it the crossover construction or the selection of their chassis. All of these Chartwells have in common, that they are built with a Rogers enclosure. Rogers itself used the second generation of the KEF chassis to built their own Black Tag LS3/5a, also very, very rare today, which was the last version were Rogers implied their own autoformers, later White Tag models8 do not no the exact serial number) used Drake manufactured autoformers, Drake delivered them also to any of the other licensees. With the White Tag Rogers, we are facing now a different B110 woofer, which is called the white belly version. The reason for that is a characteristic white glue surrounding we will find around the dust cap of the B110. The White Belly period was maybe the last well regarded epoch, were the best 15 Ohm LS3/5a were manufactured. After that period the different licensees began to deliver a somewhat cheaper quality, which also reflects in a lower price tag, because nobody wanted to pay serious money for such a little speaker except the studio professionals – but on the other hand this little gem was very costly to produce.

The 11 Ohm period

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This is the last period were original LS3/5a were manufactured. As KEF had too much variation in their chassis production, the BBC stopped the traditional way the LS3/5a was produced and opted for one standard crossover, made by KEF for all licensees, and some special selection procedere in which the manufacturers of the LS3/5a had to guarantee a low variation. In those years Harbeth started as a licensee in the LS3/5a scene and delivered as the first company in the history of audio a computer / laser technology to get a precise chassis selection. Harbeth was also the most outstanding company regarding the woodwork of the LS3/5a enclosure. I never had problems with a leaky enclosure of any Harbeth LS3/5a, which can not be said about the Rogers built quality in this period.

A not so well known fact is, that Rogers produced and labeled their speaker enclosures in advance – so they were somewhat surprised by the new BBC “rules” and as they already had a couple of speaker cabinets ready to ship, the kept the 15 Ohm badge at the back of the speakers but put the complete 11 Ohm hardware in those….born was the pseudo 15 Ohm Ls3/5a – which is today something for the collectors…

Another funny story might be the fact, that KEF as the only supplier for the famous chassis for the LS3/5a never made their own model of the little legend until they ceased the production of the B110 and T50 tweeter. KEF produced at the very end of the LS3/5a production their own limited edition – the KEF Raymond Cook Signature model.

The day after tomorrow

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As KEF stopped producing any original chassis for a licensed LS3/5a the different manufacturers went on – for a long, long period of time there was no LS3/5a anymore available. Instead of that the market saw some BBC inspired constructions like the Harbeth P3 ESR or different Spendor models just to name a few. Meanwhile it was the last fashion to discredit the little British monitor, statements like “typical British mid bass bump”, “typical British mini monitor” was en vogue at the end of the 80ties and during the 90ties (last century). The typical British monitor sound was not anymore modern, manufacturers as Dynaudio developed the basic concept to new standards with their Contour 1.3 using their superb Esotar tweeters and the famous Dynaudio bass chassis. But during the 90ties a proper floor standing  speaker was the latest fashion, so that small 2 way monitor speakers were mostly entry level models for those who cannot afford a “proper” speaker. The situation changed with the High End audio scene in the far east. Those HiFi fans in the big metropolis share one big problem, and this is space….It is nearly prohibitively expensive to have a dedicated listening room in the big cities like Tokyo, Hongkong, Kuala Lumpur or Singapore….. The LS3/5a began  to establish a sort of cult status in that particular region of the world. At the specific forums dedicated to the little British queen you might find installations were we western devotees rub our eyes in disbelieve. You will detect Kondo Ongaku amplifiers driving some Chartwell I or vintage Marantz 2 monoblocks doing the same with Rogers Gold Tag speakers. Ultra quality front end products are used, Micro Seiki 5000 turntables with Ikeda carts, tape machines like the little Nagra IVs or top end CD players or DA converters can be observed – amazing….

Here and now

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The industry started to think about the rebirth of the LS3/5a since a couple of years – because all the manufacturers from the past are also aware of the fact, that an original pair of Rogers Gold Tag or Chartwell I will reach prices in the used market which are ridiculous. Sums around 5000,- US dollars for a pair in mint condition is nothing special in our days – such evolution awakes the industry….

We can buy today an original LS3/5a again, and it is made by Falcon Acoustic, which developed in the last years both KEF chassis again and built now the one and only real 15 Ohm incarnation of the little legend. Stirling Broadcast did the same with the 11 Ohm model a couple of years bevor Falcon came up with a proper reincarnation of the 15 Ohm LS3/5a. They use speaker chassis from Scan Speak and SEAS – and they did an amazing job to mimic the original sound which resulted in a BBC approval – so the Stirling are the one and only LS3/5a without original KEF speaker chassis or recreations of them, which ever got the “go” from the BBC. Stirling called their 11 Ohm reincarnation V2, which tells us, that they do not use the original KEF chassis (Stirling had also an older version with used the last KEF chassis available). The modern Falcon also received the blessing of the BBC, so we have two very addictive possibilities today to buy a brad new LS3/5a which is made to the BBC specifications.

If you are not completely into the puzzeling details to differentiate an original LS3/5a against some modified “Frankenstein” types – my advice is – get a new one…. It is far too risky to spent €3000,- – 4000,- for a Chartwell 1 or Rogers Gold Tag were nothing is anymore in its original state moreover the wooden enclosure….

Why is this little dwarf so special???

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If you never listened to a well set up LS3/5a system, you wont believe, what these little shoeboxes are able to achieve. The miniatured size enables them to sound like a true point source speaker system. Hence these little monsters can disappear completely as a sound source, the instruments as also the center stage enfolds in your room in a fashion, that you might think about magic. The omnidirectional performance is one of the best I ever found on any speaker. You can almost enjoy them if they are listened with the back of the speaker pointing toward you….ok – that is a little bit overpraised – but you get, what I try to explain. The phenomenal omnidirectional characteristic means also, that you have to listen to them in a acoustical treated room, because such special behaviour of any given speaker will react in a critical way, if too much early reflections are mated with the direct sound pressure level. If you position them wisely, which I will explain in a minute, you can achieve a bass response you wont believe…. The speed and agility is breathtaking as is the unreal truthful rendering of the whole midrange. The resolution these little speakers are capable of is also astonishing. Mating them with a cheap amplifier and a mediocre CD player does not justice to them!!!!!!! They have the ability to grow with any upgrade you will make in your stereo system – may it the front end, the preamplifier or the amplifier….they are audio microscopes without being nasty – you can listen for hours without getting tiered…

If I should name the three most revealing speaker systems regarding midrange pureness, I would opt for the Quad ESL 57, the Western Electric 755 and the 15 Ohm LS3/5a!

Room placement

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As any high performance speaker system also the little LS3/5a is very demanding about proper implementation in your HiFi system and room placement. If you have a rectangular room at your disposal please choose the long wall to place the speakers on it. In every rectangular room with the speaker positioned at the long wall we will have an energy maxima (room mode) at 40hz around 1 – 1,5m in front of the long walls. This might be a nightmare for an American floorstander like a Wilson Audio Whatt / Puppy system 7 – but it is the chance to do a miracle on a full range sound of a little mini monitor speaker system. The LS3/5a has a frequency response which reaches out to nearly 70hz – than there is a smooth roll off towards the deepest octaves. As the British queen is constructed with a sealed enclosure, the little speaker does not behave like a ported construction, which cuts off its sound pressure level at the resonance frequency of the ports. The LS3/5a will reproduce frequencies till nearly 30hz – but it will do that with no serious sound pressure level anymore – because we have a too little membrane surface and an enclosure with much too restricted volume. But if we can place the LS3a in front of the long wall in our listening room a couple of miracles will happen. First the 40hz mode in our room will be triggered by the speaker – so that we get a frequency response at the listening position, which shows nearly no drop in energy till around 45hz – and – which is even more spectacular – at the position were we have an energy peak around 40hz in our room, we will have a decrease in sound pressure level at around 130hz – and there the LS3/5a has its characteristic bass bump – which is cool for near field listening – but not so much appreciated if we listen to some classic music at mid field distances. So we gain two very important aspects – only with the fact that we choose the long wall of our room – we get bass reinforcement and we get rid of the 130hz bump. The bass reinforcement is also not comparable to the trick Audio Note UK is proclaiming in which their speakers have to be placed in a corner….the LS3/5a placement is much more versatile and elegant!

Now lets talk about the distance towards the rear wall….as I explained in the chapter above, it is nearly fixed, if we want to trigger the 40hz mode – which results in a position around 1,2 – 1,5m in front of the wall. So we do not start without having any clue – but that said – it is not in any way insignificant to dial in the proper distance. The LS3/5a will react in a very, very sensitive way….

Toeing in

The next critical parameter is the angle in which the speaker is pointed towards the listening position. Normally we would angle the speakers at 30° towards us, with a right triangle placement already achieved. But with the LS3/5a it is a different kettle of fish…..You can use a full angled placrment towards your listening position, which is always a good thing, if your room is very reflective. But if you have achieved a somewhat good domestic listening acoustic in you room with not too many reflective surfaces around the speaker – you can choose a different positioning model. In this model we use a toeing in of not more than 7° – which is nearly nothing…..

Now lets listen to some music with a strong center fill – a well recorded vocal surrounded by some natural instruments.  If we compare the 30° method against the 7° method we wont believe, what is now going on. With the 7° model we gain a lot – I mean A LOT more centerfill – a much, much larger stage, a better rendering of the recorded space as also a tremendous directional accuracy!!!!

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Now close your eyes – what you will here is astonishing – and you never, never would believe, that such a small monitor is able to produce this large sized sound performance….The speakers disappear completely, the stage reaches way beyond the position of them, the depth of the stage is breathtaking and the center of the stage with the vocal on them is directly in front of you – right there, three dimensional and real!!! The deepest impact has gained now from around 70hz towards 45hz without any loss of detail or pureness, nor speed, these little monsters will render even Trentemöllers electro music in a fashion you never thought that this would be possible. You coupled the speaker up to your room – in a fashion, that you cared about the efficiency in doing so. You do not waist any of the produced sound pressure level the little monitor is able to give us….instead you use room acoustic phenomena like modes to get the most linear frequency response in your room. Please be patient – after the first listening session one might think it is done – but the size of the speaker base, the distance to the rear wall and the listening distance must be dialed in with a lot of care. At the end of this process you might be achieved a position, were you leave the equilateral triangle in favour of a slightly smaller speaker base – do not worry….

The Stands

The quality of the stands is nearly as important as finding the best position in your room. The LS3/5a are nothing special there, because any little monitor will gain enormous quality if paired with a proper stand. The best one you can buy is the Music Tools LS3/5a stand – and – normally I am no fan of “THE BEST” – but here it is a matter of fact. The Music Tools are reincarnations of the famous Foundation LS3/5a stands which are not anymore available. The speakers are positioned on top of these stands using 4 little balls of blue tack – please read it again – LITTLE BALLS…..;-))) The LS3/5a is constructed with an enclosure that is able to resonate – and this is meant to be like that. The whole enclosure is tuned in a way that those resonances wont effect the clean frequency performance of the speakers – so you must take care of that fact. If you use a big bubble of blue tack the speaker will be dampened – it is also a very bad idea to use any kind of spikes between the speaker and its stand… Please level the speakers precisely – our goal is, that both speakers have the chance to send their soundwaves in a coherent way towards us – if one speaker is tilted to the back, the other vice versa, this is not anymore possible. Please take care also of the indentical position of both speakers in your room….if one speaker is placed  closer to a side wall than the other – ist will destroy the whole balance of the stage! As the LS3/5a have such a tremendous omnidirectional performance, it is a good idea to leave a lot of space between the speaker and the side wall to avoid reflections which will work against the law of the first wavefront….As we use the long wall of the room, this might not be a big problem, if it is, you must decrease the listening distance as also the speaker base to gain more distance to the side walls.

In Part II wie will discuss some amplification possibilities as also some construction details in depth….so

stay tuned

E. Strauss

 

4 Koetsu compared – Japanese art Part II

In this essay I try my very best to describe the difference of 4 of the most famous Koetsu cartridges, namely the Black Goldline, the Rosewood Signature, as well as the Urushi Wajima and the somewhat special Urushi Vermilion.

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The test procedere

All 4 carts were mounted in a Frank Schröder Reference SQ tonearm using two different sorts of headshell plates Frank delivers with his arms to address the different effective mass figures a specific cart needs. More precisely the Koetsu Black Goldline was mounted with the aid of an aluminium plate which delivers with the particular Reference arm a mass figure of 13g. For the Rosewood Signature as also the Koetsu Urushi Wajima I used a brass mounting plate which raises the effective mass to around 18g. The Koetsu Urushi Vermilion got again an aluminium headshell plate, because the whole cart weights a lot more than the two other wood body carts – at the end I could manage to get nearly the same effective mass adjustment as with the other carts.

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All carts were used with the same table and the same step up transformer. I opted for the Michael Ulbrich “Monster Can” with a 1:20 turn ratio, which let the Koetsu “see” 117 Ohm while getting 26db of clean uncoloured gain! As every cart had a slight variation in output voltage, letting alone the Urushi Vermilion, which delivers just half of what the others offer, I had to adjust the volume accordingly. Finally I recorded each cart with specific music examples using a 24bit/96Khz hard disc recording workstation (Pro Tools) which made adjusting for the exact same gain value an easy task. All carts were used with the the Air Tight ATE2 phono stage (read my essay to that specific type of equipment) and were judged using my beloved Quad ESL 57 as also a pair of original Chartwell 1 (restored vintage speakers) LS3/5a 15 Ohm models. During the test sessions I used also my headphone system (Grado) which hides any coloration from the room acoustics.

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I discovered, that Sugano Sans designs needed all their specific,  precise adjustments – the SRA (stylus rake angle) differs slightly between the different carts – it is just a tiny bit – but you have to adjust the VTA accordingly. The Koetsu Black showed its best performance with a VTF just a tad under 2g, while the Rosewood Signature sounded best with 1,95g. Both Urushi models liked an even smaller amount of downforce, were the optimum was found around 1,9g. If the VTF is too high all 4 Koetsus sounded dynamically compressed which also resulted in a restricted bass performance with reduced tonal content. Please do not adjust the VTF with the “help” of a test record – you will end up with a way too high amount of VTF! The same must be said for adjusting the antiskating – all four carts needed just a tiny bit of scating compensation to show a perfect tracking performance. Keep in mind that a deflected cantilever is the last thing we want to have – phase coherence and sound balance will suffer seriously, not to speak about the rubber suspension, which will give up one day – than the expensive cart is ready for a trip to Japan….

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One side note…..such a serious comparison is not done during one day, nor in two days, it needed 12days in total. Without the possibility to record the soundperformance of each cart, you are easily fooled, because hearing has a lot to do with your mood during listening sessions…Also the human ear can adapt in a few seconds to something new – even if that “New” sounds wrong – after a couple of minutes we think – oh – it is not too bad…..our brain will do the trick – and we wonder, that we get tired while listening to our favourite music. It needs time to dial in a cart to perfection, a quick and dirty adjustment is done in 15minutes – but to get the most out of the stuff it needs more music, more time and two good ears….

The Koetsu Black Goldline

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The Black is one of the best selling cartridges of the world – it has a tremendous amount of followers as also people who hate it – it is a very controversial discussed cart, which was a few years ago a good entry into the world of Koetsu. I use intentionally the past tense – because the price of the Black raised from €1600,- 10 years ago (which was a fantastic price performance ratio) – to €1800,- and now we face a price tag of around €2100 – 2500,-. And there is no upgraded technology, no bells and whistles – it is still the same Black Goldline we could buy 10 years ago. Please calculate inflation and all that stuff, and you will never – NEVER come out with an increasement of €900,- in 10 years….. I do not know were this price politic will end – one thing is presumably – with a price tag of €2500,- for the Koetsu Black it is questionable if this cart will continue to be the best selling cart in its class. I mean a Lyra Delos costs in Germany €1300,- and a Kleos under €3000,- so you have the chance to put €500,- on top and get a Kleos – or you save €1200,- and get the amazing Lyra Delos, which is a bargain in my book !

Lets stop that kind of discussion, and start to listen to the little black gem. The Goldline is a sort of sassy Koetsu sound if you compare it with the Rosewood Signature. You get a very sexy up front gesture, a vocal performance which makes you think the singer is right in front of you. A trick managed with a very strong centerfill were the stage is more intimately rendered than big and great. If you listen to Vocal Jazz it could be the last cart you will ever need…..it is in a special way spectacular. That said things change dramatical if you listen to big orchestra compositions. On Mahlers first symphony, third movement (DECCA) you will notice a strong emphasis on the lower mids and upper bass, as also a bump at the lower presence (which makes the vocals so damn sexy). The stage is not illuminated in the way I am used to it, instead of the great size of the orchestra and the recorded space, you get the feeling of a somewhat larger Jazz club. Also the demanding passages towards the end of the third movement is not an exercise the Black Goldline likes too much – it sounds strained and unorganised. If you change your music selection towards Mozart or Hayden – the picture changes dramatically, still there is the uneven frequency response, but in this case you get a warm, sensational string tone with an amazing melodiousness – it sounds soooo real – but it is not. Which brings us to a basic discussion about what is the approach of a HiFi system…is it to be neutral to the source or is it something which can make us believe that what we here is real – even if non linear distortion in any kind is involved??

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The Koetsu range of carts showed me, that both philosophies could work – not with every type of music, but in some cases the outcome was spectacular! The Black is not the right cart for heavy metal, it does not like modern classic and also no big romantic orchestra music – what it does amazingly good are smaller ensembles, singer songwriter, Jazz and especially vocal Jazz, Wiener classic and also baroque music…. We get an intimate, holistic picture with a very strong centerfill, a damn sexy vocal performance as also a warm maybe overly ripe lower midrange, which is contrasted by the fresh also emphasised upper midrange / lower presence – so you have to listen carefully….The gestalt of the presence reminds me a little bit of the DL103 which also colours this particular frequency region to minimise the distance between the singer and the listener. The micro dynamic shades the Black has to offer are very very nicely rendered – the incredible silent tracking performance might be the key to this astonishing performance. With the big dynamic swings it is a different situation – if you compare the Black with a SPU Classic, you will be aware of how big dynamic swings could sound like….and even a SPU is not the last word in this particular discipline.

If you are a listener who scores the beauty of the tone over everything else and you are not interested in romantic orchestra music nor heavy metal – this is it!….if – and this is a big IF – there would be the same price tag as a couple of years ago…I would advice you – buy it – hurry up and get one because you are in for something really special. But for €2500,- there should be a performance which is completely independent of music styles and orchestra sizes….

The Koetsu Rosewood Signature

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Listening to the Rosewood Signature, we are diving into Sugano Sans world in all its glory – it is in my opinion the first real Koetsu cart. And as I wrote in part I of this essay – it is a very steep price tag we have to pay for this experience. The Koetsu Rosewood Signature is cut from another cloth than the Black Goldline. The first thing you will notice is the amazing amount of recorded space, the width of the stage with the exactly rendered sound sources placed on it. The bass has a grown up gestalt, it is still not the sinewy delicate and amazingly fast bass of a top notch Lyra cart – but it is aesthetically fantastic. Full bodied with endless shades of colour and heft. The midsection is world class – I know nothing that can beat a Koetsu in this discepline – again millions of colours which wrap around the listener. There is a very stable center fill – but the amount of the upfront gesture is decreased. Still there is a very intimate contact to the things which are located in the center of the stage, be it a trumpet, saxophone or the still very sexy vocal performance. But the scale is now more real – there is someone standing in front of you with a 3d gestalt and it is a human being – nearly in full size – well done Koetsu!!!

The presence emphasis is hardly detectable anymore – but it is there – a tiny, tiny bit of it enables the Rosewood Signature to produce a string tone you will never forget. The Rosewood Signature has a complete grain free treble section, a very, very smooth performance, you get a good dose of that magic sparcle without any analytical touch, it is enough treble energy to make the whole sound very balanced. Everything is so masterfully voiced, that you do not be aware of all the tiny anomalies which differentiate the Rosewood Signature from the total neutral Lyra carts (Lyra is just an example – you can also use Air Tight, My Sonic Lab or Transfiguration).

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The big dynamic swings are no problem for the Rosewood – it can follow even the most demanding passages with great ease, The Rosewood still favours of the release,of a given tone over its leading edge. The cart is more about the beauty of the tone than the birth of the latter. It shows a tremendous color palette – and the sheer excitement of the music. The micro dynamic redering is amazingly well displayed, again it might be the fantastic silent ride the cart is able to achieve which results is a very, good signal to noise ratio that makes it easy for us to detect all the tiny details in the music. I would call this a totally unforced kind of resolution which does not need a shift in the treble or air region. The Rosewood performs naturally and with a wholeness which puts the gestalt of any composition in front of its molecular structure. The rhythmical performance is voiced in a special sway, which gives you a clear perspective of the groove in the music but at the same time you get this magical flow, which seems to be able to show you to any given time the most important part of the music. That makes the listening experience very easy and relaxed – even with demanding or complex music.

The Rosewood Signature is all about the Koetsu magic – nothing more and nothing less!

 

The Ursuhi Wajima

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The Wajima has a lot of what the Rosewood already brought to the table – but you get nearly in every criteria more… more tightness in the bass, more neutrality in the whole spectrum, a lot more dynamic resolution, and also much more smooth treble. Is it the silver cladded coil wire or is it the Urushi lacquer – or maybe both – but to which degree??? – I cannot tell you – because the Koetsu portfolio avoids a direct comparison of just one of the parameters. It is astonishing in which way those two ingrediences shift the sound performance to a whole new level. The miracle of the Wajimas voicing lays in its ability to show all the beauty the Rosewood is capable of – but garnished with all the High End bells and whistles. If you compare both of these gems, yo will easily detect the increased resolution – and this is not a little bit more, it is a whole new chapter. Sugano San managed to show us all that without loosing the holistic gestalt. The treble and air section is something, nobody would expect from a wood body Koetsu – airy and open, free from any colouration and very, very smooth and grainless. The treble is able to give us a tree dimensional touch, which makes cymbals and a snare drum not a flat event, instead of that, we feel a dimensional corpus sending its sound waves towards us. The bass is also different – gone is the mid bass emphasis, instead of it we get now a deep and fast bass performance which is still very, very colourful and rich in its tonal gestalt. But it acts in a faster fashion, so that the Urushi Wajima does not anymore evaluate melody over rhythmical structures – both is shown in a wonderful balanced performance. The leading edge gets more attention, while at the same time it is not decreasing the ability to render the release of a tone till it is vanished in silence. Amazing!!!! The stage is wide open – as a window and we can see all the details from the far extremes left and right towards the center as also an amazing view into the third dimension. Centerfill is traditionally a Koetsu strength – the Urushi makes no exception here, but the center section is so very well integrated into the whole stage, that I would call it a perfect rendering. What some people will miss is the sexy up front vocal performance – and yes – this is one of the reasons why hard core devotees own more than ONE Koetsu….

The Urushi Wajima leaves the fun segment of the Koetsu line up – we are now accommodated in the adult section….(not what you think….) It is a precise tool, a complete cartridge and beyond this, it is able to give you all the magic a Koetsu is so well known for.

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In my book the Koetsu Urushi carts are the pinnacle of what Koetsu is all about – not ignoring, that a stone body cart might even be a better performer – but this is a complete different chapter which detaches some of the typical sound attributes from this legendary brand.

The Koetsu Urushi Vermilion

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If you opt for this special version of an Urushi cart, you must own a phono stage with a lot of clean gain. If you use a tubed phono stage it has to be one of the high gain models, because if you try to compensate the low 0,2mV output voltage with a higher turn ratio of a step up transformer (1:30 or even higher) you will dampen the cart more heavily. With a 1:20 the cart “sees” 117 Ohm, with a 1:30 SUT the cart will be dampened with 59 Ohm – which will kill most of what the Vermilion is about. Sugano San constructed the cart with a single layer coil structure to reduce the moving mass, so the Vermilion is able to render the leading edge in a different style than the other wood body Koetsu carts will do. And this is the first thing you might detect – the Vermilion is constructed to give us a growth in speed and attack rendition. It is maybe the first Koetsu in the line up which shows the rhythmical aspects in the music with a tremendous accuracy. The miracle is – you loose nothing of the ability to render the beauty of the tone – it is like driving a Mercedes S Class but with a motor designed by Porsche…..I love it!!!! It is like squaring a circle what Sugano San achieved with the Vermilion – chapeau! If you can use a 1:20 Step Up device with a high gain tubed phono section, without any noise, it is like a miracle. All the characteristics of the Urishi Wajima are now paired with a tremendous rhythmical precision. The bass has somewhat more impact and the treble and air are more pronounced – again without the tiniest amount of grain or harshness, this little red devil is sooo smooth – but it shows you an impressive resolution. Mybe it is the first Koetsu in the portfolio which is able to render heavy metal music at its best – there is no stress even in the most compressed wall of sound sections of such music, a full distorted electric guitar sounds amazingly real, as also the lower end of the frequency spectrum punches in our stomach and we will have a big smile on our face. That said – the Vermilion is also a statement in rendering big orchestral work – even the most complex passages are performed in a casual fashion, that is on par with the best carts you can buy.

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The Vermilion is in its special way the most unlimited Koetsu cart of the wood body family – and yes – I do not think that the Platinum Signature does it in a better way – it is just a little bit different. My advice is to get the platinum magnet structure with the stone body carts – this is a suit which fits perfectly. The wood body range has its pinnacle performance in the creation of the Urushi cartridges and something very special can be found with the Vermilion.

Thank you Sugano San for all the great music!

stay tuned

E. Strauss

The Marantz CD 94 Part II – the DA converter

This essay is a follow up to the first part The Marantz CD94 – Part1 (the drive mechanism) which described the outstanding quality of the drive mechanism from Philips (CDM1 Pro). In this part (II) I will share some thoughts and tweaks  around the DA converter section of this classic vintage player.

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Modern days

As you might know the CD 94 MK I is fitted with the Philips TDA 1541 A multibit ladder dac. This is a legendary DA converter – it never got any better, just cheaper. The audiophile magazines told us all the past decades, that every new converter generation gained a much better sound quality, than the previous one – which is completely wrong. The truth is, modern bitstream DA chips already imply everything you need to get a decent analogue signal out of your digital source, be it a CD or streamed digital data. There is not much more to do for the manufacturer as to built a proper power supply, often they use two – one for the analogue section and one for the digital stages. They design some nice casework, a good styling and a tremendous accurate clock – in which some of the more serious companies do a real good job. Any manufacturer uses nearly the same stuff. Some differ in doing excessive upsampling, some offer a different clock design, and most of the serious models do a sort of overkill in the power supply department and multiplying the number of converter chips to get a higher accuracy (Accuphase). Only very, very few models are in existence, which do really something innovative, Playbackdesigns with their FPGA DA converter technology comes to mind, Aqua with its modern implementation of the last multibit DA converter generation (already NOS stuff) and maybe those modern interpreatations of the classic TDA 1541 Philips converter, we will discuss here, done by High End manufactures like Zanden or AMR. Some companies think it is a good idea to construct the analogue output stage with designing a tube circuit –  in most of the cases, it is just a buffer stage, which should colour the sound of the player. Serious tube output stages are very, very rare, companies like Acousticplan and Lampizator must be named here.

Some facts

Lets talk about some “digital lies” first…..rubbish that is repeated thousands of times which makes it not more true. Lets start with some facts:

Any conversion process will degrade the digital signal!!!!

That is hard stuff – because what is meant is every change in the source data integrity will degrade the sound. That is a matter of fact for up sampling, down sampling, oversampling (which is NO interpolation!!!!), changes in bit depth were it does not matter if we try to make out of 16 bit 24 or vice versa….EVERY CHANGE messes up the integrity of the original data.

There is no way – even for streaming services, to better the sound of the 1980ties Eurhythmics Album “Sweet Dreams” – other than a new mastering process with the original master tapes. If the original master is digital, which happened throughout the 90ties (last century) with DAT machines, and later hard disc recording workstations, the game is over – because we once converted analogue to digital – and now it is digital – and there is no way – other than converting the files to higher sampling rates and / or bit depth, which seriously degrades the original file in favour of some streaming clients, who think – “ohhhh my…..now my favourite Prince album is available in pure DSD…..It is customer´s fake!!!!

Most of the stuff at streaming platforms produced in the end of the 80ties and through the 90ties have seen a very poor AD conversion, and is just up sampled (converted) – because most of these productions had only a digital master – so there is no other way than a new mix – if the session tapes or data on a hard drive (end of the 90ties) are still available – otherwise a remastering could only deal with what was AD converted in those years – mostly not worth the money and the work!

But why was there such a bad AD conversion quality present in the first yers of the CD era???

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My own story

Let me tell you a story from my own experience….I worked 25 years in the music business as a producer and engineer. One day – it was 1993, I left my studio with an analogue master under my arm to enter my favourite mastering facility in Hamburg. The mastering engineer took my analogue tape, and told me the record company wants to have, both vinyl and a CD – so we started to measure the Studer A80 mastering machine and routed their outputs to the mastering desc a very, very high end analogue piece of audio jewelry.  I took a seat and enjoyed my mixing work – everything sounded familiar to me – a good sign – because nothing is more confusing, as if you cannot detect your own mixing work while sitting in the mastering process. The competent engineer behind the desc started with some tweaks, correcting mistakes in equalisation I did in my mix, we got rid of some emphasis in the lowest midband, gained some nice sparkle on top, so that the cymbals sounds very open and expensive. It sounded fantastic and I got more and more relaxed, because this guy worked miracles on my mixing work – Ekki was very, very happy.  After the whole sound adjustment process we transferred the the signal to the Neumann cutting lathe – and had a very nice result. Lets call it a day….!

But than the whole mess started – because we also had to create a digital master for the pressing plant…..The industry in those days brought out the CD format, an international standard, which is  in existence till the present day. Everything seems to be fine – but it was not! Because as we would witness two decades later  with the development of the SACD the commercial audio industry forgot the professionals – those people who have to create the content, the industry wanted to sell.

Instead of a very elaborated audio workstation, we had the Sony U Matic system – a technology based on a drive, which Sony originally designed to record video data on it, a processor and a pair of lousy AD and DA converters. We connected the Studer master machine to the U Matic AD converter, the signal went trough the processor and error counter (something which is non existent in modern digital days….) – and digitised the formally analogue master. The output of the Sony U Matic DA converter was now routed to the monitors – and I thought I had to kill myself. Gone was the sparkle, gone was the natural midband, gone was the warmth, gone was the recorded space – I witnessed a flat, cold, dead and ugly sound – but that was the modern high end format of those years – stunning!!!!

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In my example above, I did my mixing in the studio fully analogue – so, there would be a good chance,  with better high resolution converters available today to remaster it again to develop a true high bit, high sample rate digital stream – which would not have been possible if I had used a digital 16bit / 44.1 master. You get the point???

Today it is a matter of seconds to convert any digital signal to something which looks impressive – modern computer technology with the world class audio software on them is able to generate out of a 16bit/44.1Khz file a 196khz, 24bit data stream – but you do not gain anything – instead of that you loose quality. Lets introduce the term “BIT TRANSPARENT”. To have a bit transparent signal in terms of its original source data is the best quality you can get!!!!!!

A lot of people wonder, while the old 1988 Prince CD sounds much better than the high resolution file available at several streaming platforms – now you no why that is the case…..

So why do we choose the CD 94???

The Maranz is very well built, it has a good platine layout, a fantastic drive mechanism and a lot of space for all the tweaks we have to do, to make a giant killer out of this audio grandpa. What that means is – that NO old Marantz CD 94 from the past in its original condition used as an integrated CD player will sound very good or reference class like – far from that! – So how can we unleash the whole potential….????

 

The TDA 1541

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The Marantz is equipped with this DA converter legend – as I said above, it does not get any better than this – but first lets talk about the different TDA 1541 versions.

Philips had a grading system with their DA converters – the worst specs got the name TDA 1541 R – and the R stands for relaxed! – This Chipset was normally sold to companies who made very cheap players – so they wanted to have a nicer price tag on the very expensive TDA 1541 chips (which is way, way more expensive than ANY converter made today).

The next quality level is the TDA 1541 A – which was the standard grade chipset, which Marantz choose for the CD 94 MK I. – If we open the hood of our CD 94 MK I we will find exactly this chip which is soldered directly onto the board.

The high end converter types from Philips were the single and even more so, the double crown TDA 1541….called S1 and S2 and featured a stamped crown on their surface (or two). Be careful – today are a lot of single crown and even more so double crown fakes on disposal at ebay and other sellin platforms…as such a single crown TDA 1541 will set you back of around €250,- it is a good idea to know for sure if it is an original version or a nice artwork of some freaks….

Keep in mind, the double crown TDA 1541 is very, very rare. The one and only CD player ever made with 1541 double crown TDA chips was the Marantz CD7 – which is in my opinion one of the best players ever made – but if we are finished with our Marantz CD 94, we are soundwise very close to this audio legend – in some parameters better, in other the CD7 is unbeatable!

What we need is a single crown TDA 1541 converter – and that means also, that we have to unsolder the old A version, and instead of directly resolder the single crown version onto the board, we should opt for an IC socket, were we can plug and unplug the new converter chip if needed.

 

Recapping

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The change from a TDA 1541 A to S1 status is not the most important tweak, we have to deal with….far from that. Starting from here, you are dealing with serious electric circuitry – a basic knowledge of electric engineering is essential, and all of what you do from now on is on your own risk – please read that twice!!!!! – If you never managed to get a proper solder point forget all of the following modifications and buy a good record player!

The Marantz CD 94 is now 30 yers old – most of its time it was stored in a dark cellar because his owner upgraded it with something new (more correctly, the Marantz shares half of its “celler time” with other old digital players, which are all “upgrade victims”…think about how many CD players you owned….;-)))) All caps – and I mean ALL of them will be far away from their original specs. Most of the players which were retired, had problems with reading a CD – the owner thought it is a worn out laser mechanism – but it is not – in 99 from 100 cases, it is the electrical side of the drive mechanism – not the laser itself or the mechanism. So we have to unsolder EVERY cap and  resolder later on the best quality we can get today, which is not such a complicated task, because the quality of modern electrolytics gained immensely in the last decades. To get the work done in a proper fashion. You need the service manual – which you can find on the web (cost free) and you should be able to read a circuit diagram – of course.

I would opt for Panasonic FC caps in the power supply, in all the digital circuits SANYO OSCON is a very good idea – because they behave very stable at different temperature conditions…Be careful – OSCON cpas are widely available in SMD (surface mounted devices) versions – to find the standard mount version is often not an easy task – but they are existent. In the analogue stage I used Rubicon, and Cerafine, as also Elna Silmic caps – if you can find Black Gates – and have the money – feel free to buy them – but they are nearly vanished even on selling platforms like ebay.

PLEASE – do the recap work section by section…and if you are tired – leave the solder iron alone and go to bed – because every electrolytic capacitor is directional, and if you are tired it happens that……;-)))) Do function tests on a regular basis, if you are finished with one section – if there is a mistake, you will have a much better chance to find the problem fast and easy.

If you replace the big power supply caps (5 of them not only the big twin towers) I would opt for slightly larger capacity – and I mean slightly (10 % ) otherwise the original power transformer cannot handle your nice tuning!

The biggest improvement

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After the recapping is done you have the rare opportunity to listen to a Marantz CD 94 in quasi new condition – and you will be impressed – there are more CD players in existence today which sound much, much worse than that old machine. But until you tweak the player any further there is no chance to play in the same league were the best players are at home….

The Marantz CD 94 – as most of the other TDA 1541 players have one serious problem in common, and this is the power supply regulators – or better, the amount of them. One regulator in the original design handles nearly all digital stages – and here is our biggest problem. The TDA 1541 needs a daughter chip which is called 7220 – and this thing pollutes a lot of digital rubbish in our rail which supplies also the DA converter, the clock and digital periphery. So we have to take care of that. As you might noticed, every Philips design in this period of time had those cooling fins at the back of the players. In the original design there are 3 discrete power regulators attached to those cooling fins – and we have to double that! Our goal is to give the TDA 1541 a separate rail – without any influence of the “dirty” 7220 – and we will do the same with the 7220 itself und the clock.

So we have to design 3 new power regulators (discrete) and connect them with the corresponding parts on our circuit board bypassing the original power traces, so that all 3 devices (TDA 1541, 7220 and clock) are directly fed with their supply voltages. We are must mount the hot transistors of our discrete regulators to the same cooling device as the already existent three original regulators. To distribute the clean supply voltage, use good quality solid core copper cables, and twist them tightly to gain some shielding.

Now we have reached a lot more sound quality – the truth is – you wont think it is still the same player….it is that impressive!

Further improvements

If you like, you can install now  a new high end clock – there are different manufacturers in existence, I would opt for a Tental Labs solution…which fits perfectly into the CD94. They supply their clock with a good manual and it is an easy task, if you already managed our journey to this point.

The analogue output stage

Now things become very interesting again…You can decide if you want to get rid of the whole de emphasis circuit, because (I bet??) you will have not a single CD in you collection, which is coded with emphasis (which was a very old technology in the first years of CD production to gain SR ratio).

What you seriously have to do, is get rid of the 4 poor op amps soldered directly onto the board. To do so, buy some very good quality IC sockets – because (I know you very well) you want to experiment with different OP amp designs. Keep in mind – just pulling out one Op amp and replace it by another one is not the way that game works, because EVERY high bandwith OP amp today needs its proper implementation – so read the papers….and do your homework!

A good choice will be the Burr Brown OPA 627 single (all 4 OP amps are single types). You can also go full throttle and buy some discrete OP amps from companies like Burson Audio – and if that is not enough, you can use Daniel Weiss devices from Switzerland – they are very, very good, but also very expensive – and they need proper implementation, which means a complete redesign of the IV stage and filter design!!!! – Which is a lot of work and needs serious know how.

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I opted for Burson Audio, which are way better than any integrated OP in this player (not always the case) and not even in the same galaxy, than what was used in the original design of the CD94!

All Philips TDA 1541 implementations (there are two exceptions) have a DC offset at the analogue output section of the IV stage – which we have to get rid of. The way to do so ist a coupling capacitor directly in front of our output sockets. Here you have to calculate the capacity of the cap – which determine the lowest frequency your player will be able to produce…a figure around 22mF would be perfect. You can search for some really good caps in the high end accessory market. Keep in mind, that you need for the best of them (and the most expensive ones) a lot of space, which you don´t have. And – if you use a big, big silver foil mega hyper cap – you will have very long connection legs, which is not a good thing! I used Mundorf tin foil caps, which are not so big – and fits very nicely into the player – but there are much more options on the market – do not go mad here – it is just one single detail!

Next step would be to get rid of the RCA terminals Marantz used in this player – do not ask me why – but that is the cheapest rubbish you ever have seen. Buy some good tellur copper RCA sockets and solder the output coupling caps directly to the sockets – and you are done! Further improvements can be achived if you change the diodes in the rectifier section of the player. It is also a good idea to deactivate the headphone amplifier of the CD94.

One last word……as all these modifications means a lot of work that has to be done, do yourself a favour and buy only good original parts, leave out ebay and any cheap offerings, their might be a good chance to get copies of the original stuff…..

The Sound

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Now you experienced what it means to implement a TDA 1541 near to perfection – there are way more tweaks you can do – but what I explained here are the most important ones – to go any further is another story maybe for part III???.

I had the chance to compare the Marantz CD 94 to the lates Naim triple 5 streaming DAC (also a ladder dac design!!!), as also the smaller Aqua DAC and the second best Plaback Designs CD player – and guess what – our old Marantz machine is in the same league. It does not sound equal – of course not – but it is the same level of quality. What we always have, if we implement a TDA 1541 near perfection, is a once in a lifetime digital treble experience. The TDA sounds creamy, smooth and has a tremendous resolution. This resolution has nothing to do, with a tilted up, analytic top end –  this treble is natural, real, and relaxed. I am not a big fan to modify the Marantz CD94 with a tubed output stage, because this modification makes things too soft, too polite – and as I use a full tubed amplifier system behind the player, it would be too much of a good thing. What you also will detect is a tremendous bass performance. The bass gestalt is powerful and deep – really deep, as also tight and very agile – it is one of the most impressive bass performances of any DA converter which is in existence till now. This bass gives your analogue rig a good workout, only the best cartridges (also very expensive) can muster the bass quality of this vintage (modified) CD player. In the midrange we will miss some of the 3D magic our analogue front end is capable of – but that is often a matter of the different mastering techniques used with the media CD – because it has to be very loud (loudness war – another story, I will write about in the future) – so you will face a completely compressed sound on the CD, which is not so much existent on the vinyl mastering of the same production, because such loud and compressed signals are not easy to cut into vinyl. What you also miss is the attack accuracy a Lyra cartridge can give you – but there is a tweak for that at the end of this essay. To make a long story short, the Marantz CD 94 in its modified incarnation sounds close to an EMT TSD 15 cart – BOOOOOM!

The last tweak

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Everyone is talking about Non Over Sampling (NOS) today – it is the newest fashion to get rid of oversampling artefacts, which degrade the pure digital signal (time domain). Oversampling was at the very beginning of the CD era a trick from Philips, as they had just a 14 bit DA converter to offer, while Sony could develop a true 16 bit chip. This is the reason why Philips introduced oversampling – to get 16 bit resolution out of a native 14 bit DAC – and they succeeded. Later on, the situation was comparable to the run for the highest megapixel camera. People do not understand digital technology, they have no knowledge about pixel pitch and all the problems a higher number of megapixel will bring to the game – more is always better – and so we will face in the next years 48mp digital cameras – and nobody knows why a 24mp file looks much better.

The same was going on in the late 80ties and beginning of the 90ties – as multibit DAC technology was the latest fashion. We witnessed the oversampling race…

It starts with 4 times and ends with 16 times oversampling processes…what the people did not realise: With every increase of the oversampling factor, the industry had to work seriously on the speed and accuracy of the clock. DSP technology was not developed in those yers, so instead of that the industry used quarz PLL clock systems. The sound of these  player generation got worse – because of clocking inaccuracy (jitter) – but the consumer had his higher oversampling rate – GREAT!

We can modify the Marantz CD 94 / TDA 1541 to be converted into a NOS DAC without any digital filtering – it is an easy modification, and many, many websites describe, how that modification is done. What you gain is more timing accuracy – because every steep filter (digital or analogue) will deliver a sort of pre ringing (and ripple). You get 3 cycles (worst) in front of the natural leading edge of a tone.  Once you compared the same player with and without oversampling, you will be stunned. Interestingly enough the US company Wadia discovered exactly those phenomena already a long time ago….

But nothing is gained without something we loose –  the frequency linearity of our player will suffer after we converted the CD94 to NOS – which means we get a drop in treble energy around 3db at 20Khz with a soft roll off. So you have to choose, accuracy in the time domain versus frequency linearity in the treble section. I opted for the timing accuracy and did everything I could do, to get the last drop of openes out of the player, which is also the reason, why I did not imply a tubed output stage at this point. Finally you get a very, very serious CD machine with all the above discussed tweaks and modifications. If there is no vinyl available, you can easily buy the CD and enjoy it immensely….and that is, why I did all that work….

Happy listening

 

E. Strauss

 

The Koetsu story – Japanese art Part I

 

There is something special about Japan, tradition and modern high tech are often separated with only a very small distance from each other. The attention to even the smallest detail in some of the best products coming from the land of the rising sun is outstanding – and on the other hand you have mass market products, ugly and very cheaply made. A land full of extremes and contrasts, stuffed cities and beautiful zen gardens amidst them, meditation and extremely noisy gaming rooms, young girls dressed with school uniforms to animate…. and buddhist monks, shinto shrines and fast food…..you get the picture.

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In the past the Japanese industry copied the stuff from the western world – the camera industry comes to mind – and especially German Leica, Rolleiflex and Contax models. But once they got the idea behind a construction, the Japanese engineers had the ability to increase the amount of features as well as the quality and they achieved a better result than the formerly copied product. At that moment there was no German camera industry anymore (Leica survived almost…) and Nikon with their legendary F and F2 models took over the complete professional camera market. If those people do something really seriously, they are able to achieve superlative product qualities.

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Imagine – at the end of the 70ties (last century) Sugano San (the father) came up with something like a Koetsu Red (read Rosewood Signature) cartridge – it was nearly comparable with the presence of the space shuttle in the 19th century….

A line contact stylus, boron cantilever, smarium cobalt magnets, 5 ohm DC resistance and healthy 0.4mV output voltage, bodies made from rosewood, lacquered with Urushi, or even milled out of  solid stone…imagine that at the end of the 70ties…..it was THE ULTIMATE CARTRIDGE!

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If we google Koetsu cartridges today, we will find a lot of forum entries, mostly comprised with misinformation, or completely wrong statements. It is a good source of amusement for the analogue lover….. If wie google Koetsu Black, we will find statements like -“great for voices – rolled off at the top and muddy bass” – than we see a picture of such a Koetsu Black mounted in a Rega RB 300 at the same thread…….on another forum a respected guy is telling us, that the golden flakes dressed upon the Urushi lacquer will result in a much heavier cartridge housing….bullshit!!!!

All forum “informations” have in common that a Koetsu is soft at the treble, has a muddy soft bass and great mid frequency response with a strong emphasis in that section, while it is a bad tracker, which is not able to track the 70 mü torture track on a test record… and is extremely sensitive to VTA adjustment. Some say these cartridges have a ridiculous stiff suspension others claim exactly the opposite, and some others think the VTA must be up at the back of the tonearm – and the majority claims down at the back may be the only way to get a proper sound. Not to mention the different suggestions regarding the termination of the carts – the range goes from 30 Ohm – 1 Kohm or completely open, which means normally 47 Kohm…..Maybe it is time to explain some things???

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The Differences

Lets start with some information regarding the different models…. All Koetsu carts have something in common….They all share 5 Ohm DC resistance, and they all share the same diamond cut, a custom made variation of a line contact stylus,  made to Sugano Sans specification by the Japanese specialist Ogura (which is also used by Lyra with a different profile leaving out the Lyra Delos which uses a Namiki needle). They all use a classic magnetic circuit wich includes a traditional yoke construction.

Here is, in what they differ:

Koetsu Black Goldline

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The only Koetsu with an aluminium body structure today (the original Urushi carts made by Sugano San the father were also based on an aluminium enclosure…) which has also a different form factor compared with the more expensive models. The body is somewhat smaller and has a different gestalt at the front of the enclosure – here we will find a angled cut, which makes us able to observe the cantilever very easy, something which can not be said about the classic Koetsu body shape of the bigger models. The Black has 0.4mV output and 5 Ohm DC resistance, which is achieved with 6n pure copper windings on their coils, and a smarium cobalt magnet. The suspension is somewhat different than the more expensive models – it has a compliance of around 13cu, which makes it compatible to lightweight tonearms, which is also addressed by the aluminium enclosure wich is more heavy than the Rosewood Standrad. The Body has no threaded mounting holes – so you have to deal with tiny screws and even smaller nuts. The cartridge features now silver cartridge pins – older models have golden ones. The modern Black (Goldline) has nicely chamfered golden lines at the edges of the body, which is represented in its name. The bottom of the cart is sealed with the classic thin sheet metal strip with the famous Japanese writing engraved.

The Koetsu Rosewood Standard

The Standard has the same body form factor as the black – we do not get at this point the longer body with the nearly straight edges, which describes a traditional Koetsu model (leaving out the first longbody Koetsu carts) ….but in this case the body is made of rosewood which gives the cartridge its name. The Standard has already the suspension, we will find on the “bigger” Koetsu carts – so it is much stiffer that that of the Black Goldline – between 8 and 9cu….which means, we need a heavier arm! That is very important, because the whole cart is lighter than the Black – so the body structure does not help us with the need of a proper tonearm mass which should reach around 18g (effective mass)! Here we have the first of a long row of common mistakes – a Koetsu Rosewood Standard is not a good match with a SME Series IV or V nor is it in any way compatible to a Rega or a Linn…..if you match the cart with such tonearms – please read the forum entries about rolled off treble and muddy bass…..;-)))) The Rosewood Standard has no threaded mounting holes  either – so you deal again with tiny screws and even tinier nuts….All of its ingredients are equal to the Black Goldline – except for the suspension and the body material.

The Koetsu Rosewood Signature

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With the Signature version of the Rosewood model we get now the traditional Koetsu body shape – gone is the lifted section at the bottom of  cartridge front – but,  be aware – the body is not a straight rectangle construction – the form of the underside is not  parallel to the top of the cart. Again we will get 6n pure copper coils, the stiffer classic Koetsu suspension, 5 Ohm DC resistance and 0.4mV output and again no threaded mounting holes. But Koetsu put on underneath a better quality control and uses more pure materials with the Signature version. What we can see as a costumer is just the traditional body structure which has now the very famous scoop at the bottom plate which protects the enclosure from dust.

In my book the Koetsu Rosewood Signature is the first true Koetsu in the line up – the Standard and even more so the Black Goldline gives you a taste of what you can expect using the Signature. This statement is true for such people, who have a heavier tonearm, for installations which uses an 8 – 12g arm, the Black Goldline would be a much better choice. The bad thing about the Rosewood Signature is its price tag – if I claim that at this point the famous Koetsu sound starts in its purest fashion – it is a very expensive entry level – which it is.

The Koetsu Urushi

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There is no sich thing as THE URUSHI – because Koetsu delivers different models – leaving out the Koetsu Urushi Vermilion, which I will talk about in a minute. All of the other Urushi cartridges are technical equal – what differs is the amazing lacquer artwork in the traditional Japanese Urushi fashion. Some of the models are made with very old techniques, and they are named after the Japanese cities in which these techniques were invented – examples are the Wajima and the Tsugaru. Others use a more modern twist to the old traditional techniques, the Sky Blue comes to mind. Urushi lacquer is a natural product which is won out of tree resin. It needs a long, long time to get fully dry and as it gets dry it gets harder and harder. Underneath the Urushi lacquer – you might guess it already, we will find – a rosewood body….so the Urushi carts use the same material and body form factor as the Rosewood Signature – the difference is the lacquer technique which gives the body a different behaviour regarding mechanical energy transmission and resonances! Technically there is also something new to discover….we still have a 6n pure copper coil but in this case it is caldded with silver. The cladding process could be explained if you imagine your girlfriend or wife putting on her sexy nylon stockings….. So the silver is not melted upon the copper nor is it a hybrid material mixture – it is still pure copper with a very thin cladded silver layer on top. The magnets circuit uses still smarium cobalt material as we get it also from the entry level Black Goldline, but – SURPRISE!!!! we will have now treaded mounting holes – THANK YOU KOETSU!!!!!

The Koetsu Urushi Vermilion

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The only Urushi which differs completely from all the other beautiful carts in this range is the Vermilion….It is easy to detect – because it is the one and only Urushi which is made out of the special red Urushi lacquer which we will also find in traditional Japanese tea equipment, tablets or old jewelry boxes. It has also a slightly different form factor around the engraved section were the mounting bolts are located – the Rosewood Signature as also the other Urushi carts have a straight half tubed engraving  – the Vermilion has a sort of triangular cut out at this section of the body. Technically the Vermilion is a total different beast, than all the other Koetsu carts we already discussed. The DC resistance is still 5 Ohm – but the output drops down to very low 0,2mV – which is caused by a single layer 6n copper coil (no silver cladding is used), were the other Koetsu carts use a double layer coil construction. In addition to that Sugano San opted for a different magnet material – the Vermilion uses an alnico magnet circuit, wich raises the weight of the cart noticeably, compared to the other wood body models. The little red beauty is the Koetsu with the lowest output voltage – so make sure, that your phono stage can handle that thing. If you think about using it with a tubed phono stage together with a step up transformer – you need a high gain phono stage with around 45db of clean gain!

The Koetsu Rosewood Signature Platinum

With the Rosewood Signature Platinum (RSP) we face a completely new technical chapter in the Koetsu line up because the cartridge uses platinum magnets…Those magnet material has a legendary reputation as all Lyra aficinoados will confirm. Think about the original Lyra Parnassus – and more so the Olympos which used the magnets of the Parnassus and is till the present day a true legend in the world of cost no object cartridges!

Based on this point every Koetsu cart uses this magnet construction. The choose of platinum magnets causes a drop in the output voltage from 0,4mV to 0,3mV, while still having 5 Ohm DC resistance. The housing of the RSP is again Rosewood as the Standard and the Signature uses it either – but in this case Koetsu chooses very old wood qualities. The RSP is the most “cost effective” way to get a platinum magnet Koetsu….which tells you something about the other platinum carts in the portfolio…..

The Stone Body Koetsu

Now we climbed up the ladder to the top, which includes also a price tag, were people, who are not involved in High End audio will buy a nice little car for the same money we have to spent at this point. If you tell your family members, that you bought a Koetsu Blue Lace Diamond Platinum for € 15 000,- there is a good chance, that your wife will incapacitate you….a white jacket and a nice soft cell included….

The complete motor system is equal to the Koetsu Rosewood Signature Platinum, which we already discussed above – the big difference is the material of the enclosure. Koetsu uses semiprecious stone. The price range differs with the rareness of the material and the expenditure to mould a cartridge enclosure out of the stone. We will find at the “bottom” of the stone body range the Onyx – and at the absolute top we have the legendary Blue Lace and the Coral Stone – the letter is so beautiful, that I cannot avert my eyes if I have the chance to look at such a damn sexy thing!!!!

The Diamond Cantilever

The Koetsu customer can order a diamond cantilever as an upgrade with every Koetsu model – while such an option will cost around €4000,- it makes no sense to think about it until you reached the stone body range – and even there it is a tough decision…..I mean 4000,- …..there are people who buy a complete HiFi system with far less, than we have to spent for this diamond cantilever!

Mono

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Another option is the opportunity to order every Koetsu cartridge as a mono version – in such a case the output voltage will be halved, which might be a serious problem with the Urushi Vermilion model (0,1mV). Koetsu uses the same construction with the mono models as with the stereo carts, but there are naturally only 2 coils in the horizontal plane. So it is not a fully dedicated mono cart regarding the sensitivity of the cantilever, which is able to move also in the vertical plane.

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If you read all the differences till that point you might think – there are only 4 different models in existence – the Black Goldline with its softer suspension, the wood bodies including the Urushi models, the Vermilion with its single layer coil structure and the platinum magnet types. And yes if you do not look close enough at the tiny differences that might be true. At the end Koetsu offers us a very, very scaled product portfolio.

If you read my article about the Lyra Etna, one thing is more than obvious:

Koetsu detected as one of the first cartridge designers the influence of different body materials. And Koetsu was also one of the first designers who found different possibilities in voicing a cartridge with coil materials and different magnet structures. A direct comparison of the various models to detect the influence of the body material or finish (read lacquer) is not possible  – because Koetsu changed also other parameters. The Rosewood Signature has a pure copper coil while the Urushi models use a silver cladded coil structure, and the Vermilion features a single layer coil as also different magnet materials.

The end of the myths

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Lets talk about some facts and get rid of the myths, presumptions and special stories…..

Effective Mass

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A lot of people who own a Linn, Rega or SME tonearm to name just a few – claim that it is not worth to buy anything better in the Koetsu lineup than the Black Goldline – which might be true from their personal perspective – because they do not own a tonearm which is able to function flawless with the other models in the lineup. If you pair a 9g effective mass arm with a Koetsu Urushi than you will detect, that the treble is rolled off and the bass is muddy and does not reach out to the deepest octave. The cartridge with its suspension reacts with the effective mass of the tonearm as a dog and its its tail….if the dog is too lightweight and the tail is heavy the dog is not anymore moving his tail – the tail is also moving the dog….you get it???? – So if we use a cart with a 9cu compliance with a 9g tonearm ist is not only the resonance frequency which gets now up to around 13hz – which might not be the biggest problem – more important is how the mechanical energy which is send from the cart into the tonearm is handled. The wood body carts help us there, because the rosewood damps a good portion of the implied energy – but if the body structure gets harder – read more direct coupling, the things get worse. A stone body Koetsu does not damp any serious amount of mechanical energy with its body structure – it acts in this parameter nearly as a Lyra cart. The Urushi carts are in between the rosewood and the stone bodies – if the body is old and the lacquer did harden over the years you have a glas like coating above your cart. Sugano San the elder used a Fidelity Research FR64S Tonearm with his creations, this beast has an effective mass of over 35g….!!!! – Todays Koetsus are not anymore as demanding in this regard – but from the Rosewood Standard on – it is not a good idea to use a Tonearm with 9 – 11g – ist is recommended to push that figure up to around 18g – and gone is the muddy bass, and the rolled off treble!!!!! The dynamic abilities gain even a greater amount of quality, and the whole thing tracks very, very good. I never got any mis – tracking from a Koetsu cartridge dropped on everything else than a test record. even the most demanding soprano voices are rendered without any harshness or stress!

Termination

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A lot of people use 1Kohm and even 47 Kohm for the Koetsu carts – in most of the cases to compensate for the soft treble gestalt (incompatible tonearms)….What you will get now is a human voice were the body has a certain natural distance to your listening position, but whenever the vocalist sings some treble implemented syllables, like S or SCH or T – than you have a miraculous beaming of the whole performance towards you – the singer is moving front to back dependant from the frequency….this is not anywhere near the real thing – nor is it nice to get such isolated, synthetic treble energy. In my book a Koetsu needs something around 100 Ohm – by the way –  the cart reacts immensely on proper termination. Do not concentrate just on the treble excitement – the bass is also heavily affected – with 1 Kohm it sounds mostly uncontrolled and muddy – so you get both horror stories with just one parameter – in your face sibiliants and a muddy uncontrolled bass….Please keep in mind – if a tonearm is not compatible with its effective mass and energy distribution, there is NOTHING you can gain – it es if you put a very big Garrett turbocharger in your 1,5 l Diesel….and wonder why there is this ugly black smoke coming out of your exhaust…. If the basic things are not addressed you can stop your attempt to get a proper sound out of your Koetsu – look elsewhere.

The critical VTA

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Yes it is true a Koetsu reacts in a distinct way if you change the VTA – but it is also true for every other cart which uses such a sharp cut….so the Koetsu is nothing special here!. Put a record on your table, it should be music with a voice in the mono centre of the soundstage and some naturally recorded instruments, which reaches out to the far right and left of the panorama. Now listen….with the tonearm leveled parallel to the record surface.

What you will hear is:

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The Bass is on the lightweight side of neutral – less impact, soft tone and very difficult to follow.

The upper mids and lower presence is rendered in a unnatural forward sounding way, the singer stands directly in front of you – it is very very up front – a thing – some people like…

The treble and air is nearly completely masked with the lower presence around 4Khz – so there is no real sparkle and no air….

What we normally would do is to rise the tail of the arm to get more treble – but raising the arm gives us no real treble and no air – it gives us more presence – first it starts with the lower presence and as much we raise the tail of the arm we gain more higher presence – we can tune the presence section of the spectrum – but we cannot gain real treble – nor air!!!!! – As we do so, the soundstage suffers seriously – we have no real width anymore leaving alone some pin point accuracy at the extreme edges of the stage. And the bass will suffer – it is now woody and not deep anymore…..

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So – raising the VTA is not the right direction – lets try it the other way round….and BOOOOOOOOOOOM!!!!!! – There it is – a slightly tilted down rear end of the tonearm and the sound becomes wide, and the bass shows now heft and structure, the emphasis in the presence  is now much more domesticated – and we are able to detect a good amount of natural treble and air, as also a dramatical improvement in resolution. Now you have to find the sweet spot which depends on speaker position, your room acoustic (hard but true – we spent so much money on carts and phono stages – but the real deal is the room acoustic) – their will be a point were you get the widest stage AND a clear center focus – no high mid and lower presence emphasis and a full bodied bass with a nice tonal structure. The sound is now very, very natural and realistic, and in a special way seductive and immensely beautiful. And yes a Koetsu is not a Lyra or a Transfiguration – it is something else, which is in itself fascinating, delicious and very, unique – this carts could generate a drug like sound. Nothing sounds as a Koetsu – and I mean NOTHING!!!!

Further adjustments

As with every sharp stylus cut the Koetsu reacts very  sensitive about all the typical parameters. So take your time to adjust the cart in a proper way. That is more easy said than done, because you cannot see the damn cantilever. Use a good protractor and different magnifying glasses to get the geometry spot on. Do not use the body with its straight lines – the cantilever is the only thing that counts!!!! With the azimuth use as a starting point a pencil mine which you should place on top of the headshell and not on top of the body – it might work with the Black Goldline and also the Stone bodies and the Rosewood models – but with the Urushi carts, there is a great chance, that the lacquer is much too uneven to get a proper result. After you have adjusted the azimuth basically, put on a mono record on your turntable – switch the cartridge connection cables of one channel and swith your preamplifier to mono…..Now you should here nearly nothing – because the two channels should be 180° out of phase and canceling out any sound coming from the two channels. You will here some treble signals coming through – that is normal and nothing to worry about. But if you detect some serious signals in the mid spectrum or more problematic the bass, you have to dial in the azimuth in a way, that you get the maximum of cancelation between both channels. As you see, you do not need a Fozgometer or a measuring computer….you can do it with just a mono recording. And you know now, why a mono switch wich your preamp is hopefully equipped with is something very, very useful. After you are finished with your azimuth adjustment – do not forget to reconnect the tonearm cables in the proper way….;-))))

 The little details:

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Please do not use any aluminium cartridge screws as also no Delrin or heavy dampening plastic stuff – a good idea is brass, copper (even better) or – the screws Lyra sells – which are amazingly good. Please avoid also nuts made out of aluminium, which is important if you use Koetsu carts with no threaded mounting holes.

If you mount the cart – please do not overtighten the mounting bolts – you can deform the body structure and it is seldom conductive soundwise to use brutish force!

If you use a step up transformer  a 1:20 might be the best choice – if you already bought the Urushi Vermilion – make sure, that your tubes phono MM stage can handle the small amount of output this specific carts has to offer. Talking about SUT´s – the Michael Ulbrich “Monster Can” (see my Lyra Etna SL essay) will be an amazing performer – I must confess, that I never had a SUT which mated so well with any of the Koetsu cartridges – it is amazing – in particular the bass performance is astonishing! – THANK YOU MICHAEL – WELL DONE!!!!

Use a cable with a very low capacity from the SUT to your phono stage  – which is also important for your tonearm cable (in one future essay I will come bak to that…)!

One last word

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Maybe you observed on the used market some very nice Koetsu carts – mostly the mega expensive stone body carts are on offer for a big, big discount. You start reading the description of the used cart (hopefully given in a truthful way)…. “Koetsu Burma Jade – only played 100 hours, retipped by VdH – better than new…..”

Please be aware that no retipped Koetsu will sound like the original one – not a remake from Benz Micro nor one from VdH. I do not say that this carts are bad or worthless – but it is not anymore what it was. There is just one retipping company which is able to get as close to the original as possible, that is Ana Mighty Sound from France! But why should I use a retipping service if Sugano San is still alive and happy to take your order for a complete overhaul of you beloved Koetsu??? – Koetsu does not do any retippings – they do a complete remake – which is a fine thing – because you get after the procedere a brad new cart with a new unused suspension, new cantilever, new stylus – everything is brad new – they just leave your body like it is (which is also a good thing….). And they have a fair price politic for such a complete remake – and it does not need a year – it is done in 2 or 3 months. If I have spent €10 000,- on a stone body, I would not hesitate to give the cart to those, who once built it. That is the only chance to get back, what you have payed for – because – once again – no different stylus shape, no different cantilever material, length and shape and no variation in coil material and thickness will recreate what the cart once was. You get something which might plays music – but it is not anymore a Koetsu!

Which brings us to a different kind of online offerings…..an original Koetsu Urushi made by Sugano the father from 1984 in brad new condition – never played – and the price is…….ta ta ta taaa €6000,-!!!! Why would I buy a cart from 1984 – if we all know that a suspension will harden over the time – even if the cart was never used (which is a very common term today – may it a description which says  ” never played” or “not even burnt in” – or “150 hours but 5 years old” because the owner has several carts….and so on….) keep in mind every cartridge changes its technical parameters in the suspension over the time. Such an old Urushi might have a compliance of 5cu – and can hardly track any piano tone…..

There is no other cartridge type were we can observe so much bullshit as with the famous Japanese Koetsu!

If you want to have one – wait until you have the funds to buy a new one. In most of the cases it turns out as a much cheaper solution and it is even more delightful to start your journey with an original and masterfully build gem!

At the end it is one of the very rare true classic carts which offers a one of a kind sound aesthetic and is unmatched till today, because no other manufacturer comes even close to that particular sound experience.

…..happy listening

E. Strauss

Air Tight ATE 2 – a full tubed full function preamplifier

The company:

With the Japanese company Air Tight there is a lot to discover which is completely absent in todays High End scene. Product running times of more than thirty years without any MK II or upgraded version of a given amplifier is something we wont find at any other company today. If a piece of gear is developed, than it IS developed, there is no reason for any change, which says something about the quality of the development. Miura San is one of the last living legends in the audio scene, meanwhile in his mid eighties, he has a lifetime of experience in building tubed audio equipment, a sort of deep understanding seldom found in todays fast changing market were every year new completely unknown people want to tell us, they found a new technology in amplifying an audio signal. With some new technologies, like digital amplifiers, that might be true, but with tube technology???

Miura has a sort of calm style in managing his company and developing audio gear. Things need time, countless listening tests, which was very clearly seen with his Opus 1 cartridge, which Air Tight brought out two  years ago as a cooperation project between Matsudaira San (My Sonic Lab) and Miura San of Air Tight (A&M ltd.) to celebrate the 30. birthday of the company. Miura needed more than 3 years from the first prototype, shown to the press and some “insiders” for listening tests, till the final product entered the market. And between the first prototype and the final candidate, there was much more different, than just the styling of its beautiful appearance. Instead of that Miura changed a lot of details which had a tremendous impact on the sound of the final product. It is astonishing how a man in his mid eighties could achieve such a good hearing as also spending so much attention to the finest details. The fruit of his restless work was once again, as we witnessed it more than 10 years ago with the legendary PC1 Supreme cartridge, a place at the very top of todays cartridge designs. The portfolio of the small company near Osaka, which counts around 6 employees, is dedicated to the analogue music lover. There are no CD players or DA converters in existence, instead of those kind of products, Miura offers a wide range of tube pre, phono and power amplifiers, which use nearly every single famous power tube concept in existence, as the 300B, 211, EL 34, EL84, 6L6 GC and the KT88. The output power varies between 2X 8 Watts of the ATM300 to 2X 110 Watts of the ATM3 EL 34 monoblocks and is finely graduated. Not only this wide variation of power tube concepts reminds me of one of the other legends in the Japanese art of building tube equipment – …Shindo.

An indication of both companies is the fact, that the price of an amplifier has no direct influence on his sound. The smallest amp Air Tight has in their portfolio, the ATM1s is one of the finest EL 34 amplifiers I know.

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The difference in money you have to spent for the power amplifiers has more to do with the size of transformers (and their price tag) and power supplies, because a KT88 in ultra linear operation with its 2X 75 Watts needs more expensive iron, than an EL 34 amplifier, the exception of this rule concerns all single ended amplifiers. What I want to say is – in the Air Tight amplifier lineup there is no such thing as entry level and reference level in their ability to give you a maximum in soundquality! That said, things change quite a bit with the portfolio of preamplifiers – here we face a difference in fittings, be it the existence or absence of a phono sections, or the kind of outlay in which the gear is made. And even if there is a sort of range describing the quality of the different preamplifiers, there might be also some exceptions from that rule. If the little full function preamp ATC1 is mated with the previously mentioned ATM1s, (a pairing which was made for each other and was also developed together), you are in for a treat!!

The lineup includes pure line stages and full function preamplifiers with on board phono sections, as also stand alone phono preamps. The more basic (which does not mean simple or bad sounding) gear share a transistor, diode rectified power supply, as we climb up the range, we get tube rectifiers and full tube stabilisation with some of the most elaborated hybrid power supplies you will find on the market,

The Air Tight ATE2:

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Miura had the Chuzpe as an analogue lover to bring a full function preamplifier to the market, which has a full blown phono section with all bells and whistles – but he equipped the ATE2 just with one single line input. So the ATE2 is not for those audiophiles, who have a tremendous number of gear….just ONE nice FM tuner or CD player, maybe a DAC with switchable inputs (which gains the flexibility if you have more than one digital source) and you are done with the number of line inputs. On the other hand, you will find two MM inputs, switchable from the front plate, and a pair of phono direct outputs, bypassing the whole line stage with all switches, volume control and of course the tubed line gain stage.

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This additional pair of output jacks are very special and offer us different operation modes. You can plug the phono direct outputs into your favourite line stage, as you can feed the Air Tight amplifiers directly, because they all (not the ATM300) have two  switchable pairs of inputs and sensitivity potentiometers, to adjust the volume or gain. The latter will be the most pure signal flow you can achieve. With its 200 Ohm output impedance the ATE2 has no problems to drive nearly every power amplifier on the market directly. If you have a second amplifier setup in your room, those extra pair of direct phono outputs can also be used to feed a different system, while the whole full function preamplifier resides in his setup, it can distribute the phono signal fully processed (RIAA eq and gain) to another device.

The power supply:

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Miura San opted for tube rectifiers and tube stabilisatation in the power supply of the ATE2. Together with the in house produced power tranny with its 8 different outlets, we will find a single 6X4 full wave rectifier tube. Stabilistation is done with a 12BH7 double triode and a EF 86 penthode. The regulation is accomplished fully discrete using the finest components available. Miura replaces electrolytic capacities as fast as possible in favour to high voltage foil caps in the signal chain and supply voltages.  Therefor he uses the excellent  Audience (Auri Caps). Electrolytics will be found just  in the first stage of the power supply and in some regulation circuits, together with ASC paper in oil caps a reminiscence to the golden time of tube technology.

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After careful listening sessions, I opted for a GEC CV 4005 black plates in the rectifier stage, which is a British military version of the 6X4 or EZ90 (the European designation for the same tube). The two stabilisation tubes EF 86 and 12BH7 were selected with RCA 12BH7 black Plates foil d getter from the end of the fifties (last century;-)) and the legendary Telefunken EF 806S, which got this status from its use in the well known Neumann U67 microphone.

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The phonosection:

A novelty in the Air Tight portfolio is the fact, that Miura uses in each of his phono section exactly the same design – what differs is just the expenditure in its layout. The basic design features a 2 stage gain section made with 3X 12AX7 (or ECC83) double triodes. The first gain stage is made with one single 12AX7 which does just gain at this point – subsequently we will find the bass emphasis part of the RIAA curve in the signal flow,

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which is located between the first and the second gain stage to avoid noise. The second gain stage uses just one respective section of the two remaining 12AX7 double triodes, after which the signal passes the treble processing of the RIAA curve.The complete equaliser section is made by using a CR circuit, one of the simplest ways to achieve a highly accurate equalisation with a minimum of fuss and parts.

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To get a preferably low output impedance Miura designed a SRPP circuit in the decoupling stage of the ATE2 using the two remaining section of the 12AX7 (ECC83). So all in all we have 3 12AX7 (ECC83) in the phono section of all Air Tight preamplifiers with exactly the previously explained implementation. What differs is the kind of execution, the quality of the parts and the power supply. The whole amplifier is point to point wired, which also applies also to the phono section. The whole circuit is placed on a smooth copper plate, which is treated with Zappon lacquer to avoid oxidation. This copper plate has two functions, on the one hand it shields the small signals from electromagnetic pollution, on the other hand it acts as a mechanical isolation device.

The line stage:

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In the line stage of the ATE2 Miura choose ECC88 frame grid tubes . Those are naturally superior to any 12AX7 (ECC83) or 12AU7 (ECC82). With the frame grid technology the Philips group found at the pinnacle of the tube age one of the most dramatic progression in the sound quality of electron tubes. If you have the chance to peek into such a construction, you will understand that this technology signified a whole new chapter in tube design – those tubes are made like a piece of mechanical and electro mechanical art! The ATE2 uses a two stage design in their line section implemented with two ECC88 and decouples the signal with a SRPP design we already discussed with the phono section to achieve also 200 Ohm output impedance.

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The volume tracking is accomplished with one of the best possibilities next to a ladder switch, by using the very famous ALPS Japan RK 501 pot….A haptic enjoyment! This thing is extremely transparent and does not ad any coloration to the sound, as it gives you a very precise tool to adjust volume, even in very, very small increments. The stunningly even channel balance of this pot is amazing – even if it does not work in its optimal range – amazing!

Controls:

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Next to the ALPS RK 501 volume potentiometer, we will find a stereo/mono switch on the front plate of the ATE2, as also balance control and two switches for the different sources. The latter is made in a special way – you have a switch which selects line or phono, and an additional one for selecting one of the two phono MM inputs. All switches are easy maintainable if one day they need some cleaning. Both switches  do react without any noise! Last but not least we will find the power button on the right side of the front plate, which is typical for any Air Tight gear. Miura designs every piece of gear with a certain legality, the power supply sections are always at the right side of the gear as it is the power inlet.

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It is very easy to built up an Air Tight system without getting a big mess behind the gear with signal and power cables twisted together – very, well done Mr Miura! The principle of design means also, that we have to place the gear in a certain way – our goal is to get the largest distance between the power supply of our amplifier and the input section of the phono stage – and as the gear is made as it is – it is an easy task.

Tube rolling:

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As I use my beloved Quad ESL 57 with the ATE2 it is not recommended to mess up the incredible resolution and pureness of this preamp. So I opted against some very exciting Mullard long plates (MC1 long plates square getter) – because those type of tubes work perfectly with a speaker like the LS3/5a – but not with the restricted amount of highest treble energy the Quad has to offer. The KEF T50 tweeter in the LS3/5a together with the deviding network means a slight treble rise with a tremendous resolution – the T50 is able to react on frequencies over 40Khz with ease. The Quad is a different breed – the treble starts to roll off at 15Khz – and is nearly absent at 18Khz – a Mullard – as beautiful it might sound, is the last thing we need with this speaker system. One might think an Amperex would be a good choice – and yes, I tried this…. I use Amperex long plates 12Au7 and 12AX7 Foil D Getter in another preamplifier in my Quad room – but in this case, i could detect a pronounced emphasis in the prenence, which is typical for the Amperex long plates and one of the reasons for their amazing 3D abilities…. But with this specific preamplifier it was too much of a good thing…

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With the decision of proper NOS phono tubes, we also decide what kind of performance we will get regarding the noise coming from the record – all this little nasties like clicks and pops could be amplified in a way, that we will get crazy or we have a lucky smile on our face. There are NOS tubes in existence, which set these noisy signals far away from the music – they perform in such a quick way, that a click is just a short signal, with a Mullard (MC1) in a phono stage, such a click will be a real event, something I cannot live with;-))))

That does not mean, this legendary Mullard is a bad tube – far from it – but in a phono stage ist is everything else than a perfect solution!

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As you might guess – I opted for a triplet of equally numbered Telefunken ECC83 smooth plates. A tube which is sooo quiet, one of the most silent ECC83 I know. And the Telefunken can transfer those clicks and pops in something you are able to ignore – a miracle! The ECC83 Telefunken has such a balanced sound, which lets the ESL 57 shine. The bass is tight and well rendered, the mids are outstanding – maybe the reference point in this tube class (read my essay about the Telefunken ECC83 on this blog) – and last but not least we get a high unforced treble resolution, something the Quad needs so urgently! At the whole frequency spectrum the Telefunken is almost neutral – especially in the midband, which is is a MUST, if you listen to a pair of Quad ESL 57 – this little divas are able to show you the slightest amount of coloration.

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With the line tubes it was not such a clear decision, and even today, I can live with more than the single solution I finally choosed. I had some of the finest ECC88 to play with, and every single one of them has such a tremendous sound quality with some special colours, the others miss. My stash included Siemens Halske CCA, Telefunken E88CC, Amperex Bugle Boy 6922 Gold Pins and Valvo Red Label E88CC. The Siemens had the finest resolution and the tightest bass – the air this tube can deliver is outstanding, the whole amplifier starts to breathe – amazing! – But the Siemens has a slight defensive midband section, a little bit of the classic HiFi coloration. That is easy, if you listen to Jazz or Vocals as also Pop music – but if you choose one day a very good classic recording – you will detect what I mean. It is still acceptable if you listen to small orchestra music – but if you choose romantic music, like Mahler or Bruckner – it does not work…..massed strings get a synthetic touch, the overtone spectrum sounds not natural anymore….

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The Amperex has an amazing 3D rendering – it is one of the rare tubes which can tell you something about the third dimension in a given recording – you will get a real nice picture! BUT – the Amperex is also coloured –  here it is the presence area of the spectrum. This makes vocals super sexy – female singers are a sort of an erotic experience – but than you listen to some distorted guitars – and it is all over….;-)))) – The presence emphasis transfers a Metallica record to more or less something we would call noise…..yes I hear you – you think IT IS NOISE – but It is not….The guitar sound produced on this specific album is like jumping in a warm swimming pool…. It is arranged in a style comparable with a church organ – listen carefully, and you might detect this album is far from being just noise – even it is Heavy Metal!!!!!!

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The Valvo Red was amazing – as was the Telefunken E88CC – both are maybe my favourite E88CC in THIS PARTICULAR preamplifier..both share a neutral midband, both have a natural unforced resolution, the Valvo Red being a little bit recessed in rendering the highest frequencies – but not in a way, that I missed something. The Telefunken was more open, and acted quicker at the leading edge. In opposite the Valvo had a slightly more impressive bass…..if I am bored – I can change those two E88CC tubes back and forth – one month is Valvo month – followed by a Telefunken month….I started with the Telefunken E88CC!

The enclosure:

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Miura San built his gear like it was made in the golden age of tube amplifiers. There is no cheap aluminium box screwed together, instead he uses a steel enclosure of 1.3 – 1,6mm thickness welded together! After that procedere the chassis gets some solid layers of automobile paint in a baked finish. The reason for such a tremendous outlay is on one hand the perfect shielding such a faraday cage is able to accomplish, on the other hand we will detect that steel is a fantastic resonance absorber. The aluminium frontplate is just screwed on top of the steel enclosure to get a nice an stylish appearance.

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The bottom of the ATE2 is made of copper – that means that gear which stands underneath the ATE2 cannot radiate electromagnetic pollution into the fragile circuits. The whole preamp enclosure is divided into 3 main sections. One section is reserved for the power supply and separates the top deck of the ATE2 in two section using a massive copper plate.  If we turn the ATE2 over, we will find the bottom main deck, in which the complete line section is located.

The Sound:

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I own from Air Tight also the ATE 2005 stand alone phono stage, which uses the same circuit and layout as the ATE2 in its phono section. They both just differ in their power supply (and a very special MC head amp the ATE2005 features). Were the ATE 2005 uses a transistor power supply and diode rectification, as also full discrete transistor regulation, the ATE2 uses a full tubed power department.

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Both differ also in their gain layout, a consequence of the built in MC head amp in the ATE 2005…(another story…)

The ATE2 features 36db of MM phono gain, the ATE 2005 just 30db. For any comparison I had to adjust the volume accordingly – which I did. The impact of tubes in a well built power supply is clearly detectable – the ATE 2005 has a drier bass response, very tight and limitless, while the ATE2 brings a certain agility on the table with an aesthetic which is completely different from the ATE 2005. On Dancefloor, Electronic and some Pop music pieces I like this tight, deep and impactful behaviour  of the ATE 2005 very much. If we change the music style to Classic or Jazz, the ATE2 sounds more real, the bass ist more articulate, even if it is not as tight. The music beginnst to breathe, there is a sort of beauty in the bass rendering, which the transistor power supply equipped ATE 2005 cannot counter. On the other hand the ATE 2005 has a sort of openess, which the ATE2 can not muster. The Air and resolution is astonishing – while the ATE2 reacts in a smoother warmer style! Both are some of the finest tubed phono stages in existence today – and both are everything else than equal!

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The ATE2 os able to render a jet black background, the micro dynamic abilities are stunning, even the slightest shades of dynamic contrast is presented in all its glory, which is also a form of resolution, nobody speaks about today….but it is a very important type of resolution. Treble and Air resolution, which we get in spades since a couple of yers even if the whole picture drifts into analytic insignificance is one part of the story –  but what makes you sit and listen while forgetting to breathe are the finest differences in dynamic shades…I could (and do) waive the last ounce of treble and air resolution with my choice of speaker (the ESL57) but I cannot live without the finest dynamic shades – which brings – in my opinion – music to life. The ATE2 shows this ability with tremendous realism, and the ESL can transduce the whole picture in all its complexity in a very accurate way.

This preamplifier reacts very, very fast to the leading edge of a sound or instrument, and all the Quad lovers will agree, this is one of the skills were our beloved “vintage” speaker shows to most of all modern designs what attack speed is all about. You can witness the birth of a tone – what could be more beautiful….???

It is stunning what Peter Walker designed sixty years ago, which we can enjoy in all its beauty and perfection with todays elaborated moving coil transducers and high resolution (in a good way) electronics.  It reminds me of an old Leica screw mount camera with its famous Elmar 1:3.5 mated with a modern black and white film….The picture (sound picture) is in both examples a long forgotten type of aesthetics, which touches our heart. It is not a photoshopped high resolution digital picture with all its arbitrariness!!

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The ATE2 could be your last preamplifier, if you can live with just one line input, it is THAT GOOD. There might be more resolution, more bass, more treble or more macro dynamic today in the most modern and elaborated designs – but the wholeness, the natural kind of rendering this thing is capable off, differentiate real music played by real human beings from a sort of an effect dilution.

Its comparable to movie films – one needs hundreds of Avid and computer –  rendering effects to get the plot through – the other movie has just a perfect and tasteful camera mated with a fantastic script. If you have really something to say  – you just need a quiet audience…..

Think about that….

Stay tuned

 

E. Strauss

 

Lyra Etna – a pristine beauty

The construction:

If we compare the Lyra Etna SL with its more expensive stablemate, the Atlas SL, we will discover that both cartridges share the same basic technical ingredients. Both feature the same line contact stylus cut, the same diamond coated cantilever as also the same coil technology and stylus material. They even have the exact same technical data except the weight of the whole cartridge. While the Atlas is made from one solid billet of Titanium, the Etna uses just a core structure made from this very rigid material. The side elements are made of special grade aircraft aluminium press fitted with the inner Titanium core structure additionally damped with some bronze inlets, a technology that Lyra started to use in a slightly different way with the Kleos cartridge.

The Sound:

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It is somewhat a once in a lifetime experience to get the chance of comparing the sound difference between two cartridges which differs just in one single construction parameter – the body structure. This is a mindblowing experience, because it is hard to believe that just a body structure could make such a tremendous difference in the sound aesthetic which we will detect comparing the Atlas SL with the Etna SL. While the Atlas stretches the frequency extremes like no other cartridge I know, the Etna features one of the most natural mid band spectrums I am aware off. Do not think the Etna SL is rolled off at the top or has any weakness in showing anything less than the deepest octave of recorded music – far from that. But the Etna SL has such a pure and natural midband performance, that you are more aware of what happens in this frequency section, than listening to the explosive bass or treble performance the Atlas is capable off. The Etna breathes the tone, the Atlas trows it at you – both is an amazing experience. If I listen to Pop music, Electro, even Jazz, the Atlas sucks you into the performance with his sheer heft and tremendous speed and agility. The Etna SL in comparison has more flow, more natural Gestalt and an amazing integrity of the whole frequency spectrum. The dynamic abilities are also outstanding, but the sound does not so much explode in front of you, instead it unfolds a never ending colour scheme of tones and moods. There is a wide and deep stage, a tremendous realistic rendering of the recorded space – and on top of that you get a string tone to die for. The vocal performance is more integrated, than with the Atlas – there is more a human being in front of you – what you loose is the last drop of resolution and a very, very tiny bit of air around the singer. What you get instead is the body of the artist – you get a different kind of resolution – a resolution, were tiny shades of different moods, while the recording session took place, vary the vocals. Every tiny bit of feeling  – or – the soul of the music!

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Lyra does not offer a small Atlas with the introduction of the Etna – Lyra gave us audiophiles a different view of the same picture. You can choose if you want to have the thrilling experience of the Atlas or the richness in midband colours of the Etna. It is unbelievable that just the different body structure could alter the sound of an otherwise identical cartridge. Jonathan Carr showed us, that body material and the structure can “voice” a cart in very different way. I think the monoblock Titanium structure of the Atlas allowed the cartridge motor to get the highest attack precision without any kind of smoothing out those first few milliseconds, while the Aluminium / Titan structure of the Etna emphases the resolution in the mid band – and rounds even so slightly the the leading edge.

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Mating the Etna SL with a phono stage – tubed or transistor, as well as finding the right step up transformer might be challenging. If a cart has such a fantastic mid band purity, the last thing we would want is any colouration in this very important range. I opted for a tubed phono stage, and with this decision, you start to think about the right tubes to choose in this regard. Mullard and Amperex are well known for their low midband emphasis (Mullard MC1 Long Plates) and a certain offensive character in the presence department of the sound  spectrum(Amperex Foil D Getter Long Plates). To find really uncoloured tubes of the ECC family lets you think about Telefunken and very old Valvo ECC83 (M1 or MC2). Both tubes can give you an uncoloured midband performance while also having a tight grip on the bass and a sweet unforced treble aesthetic. With a tubes phono stage there is in most cases the need for a step up transformer – the Etna SL has a very low inner resistance and give us just 0,25mV, which calls for a 1:20 or 1:30 step up device depending on the gain of your phono mm section.

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That brings me to one still relatively unknown transformer made here in Berlin by Michael Ulbrich and his company Consolidated Audio. At the beginning of 2019 I got my copper wound nano 1:20 transformer – and the pairing with the Lyra Etna SL is nothing short of spectacular. Michael succeeded in designing a SUT which is very, very transparent to the source. All starts with a speed this device is capable off, so that you get the last ounce of the leading edge – and – very important, the clicks and crackles are just very, very short signals – there is no tendency to lengthen those on the time axis. A short click is, what it is – there is no rounding, no smoothing and no side effects. This ultra fast reaction lets us “hear trough” all the clicks an crackles on our beloved vinyl. As I also work on vinyl restoration, I did some tests and comparisons regarding this aspect with other well regarded step up devices. If you transcribe the vinyl record to a digital workstation, you can measure the attack performance versus the timeline. What I found out is, that most of the SUT I had in for comparison do a more or less rounding on the leading edge of a click or the signal. With the Consolidated Audio SUT all those little nasties are clearly differentiable from the music – they get out of our musical awareness – awesome!

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The “Monster Can” is shielded very well against electromagnetic interference – you can place it wherever you want – even near a power transformer there is no hum. All the typical High End rituals, like dressing the cables, finding the right position in your rack (most often the hum is gone if you hold the SUT in your hand, were no rack shelf is in existence;-)) are forgotten…Just find a place were you have enough height in your audio furniture, because the thing is big – really big!

With the “Monster Can” Michael Ulbrich also gave us the possibility to terminate our cartridge with resistor plugs. Between the input and output section you will find one extra RCA terminal per channel to plug in those resistor equipped RCA connectors. The built quality is outstanding – and the attention to detail second to none. The “Monser Can” comes with very smooth rubber feet – so any isolation platform is obsolete – and those feet hold the heavy thing securely in its place. All terminals are of the finest quality as is the built finish of the whole enclosure.

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Sound-wise this thing is close to a wire with gain – do not expect an overly warm and coloured SUT sound – the Consolidated Audio device is very, very transparent – maybe the most spectacular aspect is the pureness of the mid frequencies as well as the unlimited bass fundament which it is able to produce. There is a complete absence of any harshness or artefacts – just music. Well done Micha Ulbrich, WELL DONE!!

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If you pair the “Monster Can” with a low capacitance cable between the SUT and the input of your phono MM section, you are in for a treat. The Lyra Phonopipe does an impressive job in this regard, and the Etna SL begins to breathe. The string tone is spookily realistic, creating a 3D impression of the musical performance. Listen to a well recorded piano and you might think the damn thing is standing in your room – amazing!  If someone would have told us 15 years ago, that such mega performing carts, step up devices and tonearms would be available…..

It is very interesting what a huge step some of the cartridge manufacturers are meanwhile able to muster. The biggest downside is a very steep price tag such beauties have in our days – the race towards the € 20.000 is on – and we will see if this limit will be reached this or the next year. That is one of the biggest problems in the serious music reproduction industry – because young people, listening to music via their mobile phone and a docking station will be shocked if they enter a HiFi shop today and become aware of the sometimes completely over the top price tags. Lyra created one big exception from this course – they brought the Delos onto the market, the fist cart in the line up with the new specific damper technology. The Delos is also not cheap, but what J. Carr developed for €1300 is amazing! – In other words – it needs a very, very fine record player and tonearm to unleash what the Delos has to offer. And the price tag – a hint for all the crazy “what´s best” guys….the price tag says nothing about the quality of this awesome cart. If J. Carr would double the price – it would still punch above his weight.

Happy listening

 

E Strauss

 

 

Lyra Atlas SL – the Shaolin fighter

If there is anything I would call the best phonographic cartridge…..

it would be the Lyra Atlas SL!

Normally it is very difficult to speak about “the best” in terms of audio equipment – because “the best” is most often system dependent and also personal preferences are a big deal in ranking such devices. But nevertheless, in this special case I would establish “the best” and here are the reasons why:

Construction:

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Jonathan Carr of Lyra is one of those rare cartridge developers, who raised the bar with every new generation of high end pick up systems his company brought to the High End market. May it be the legendary Lyra Parnassus, the Lyra Titan i or today the Atlas, all these cartridges refined the performance of analogue sound reproduction tremendously. Jonathan seems to be one of those exeptional people in the audio industry, who are not satisfied with what is possible today and he is also able to think in a more radical way than others in terms of technological development. The new Lyra Atlas SL has a bunch of technical specials which are not seen in any other cartridge.

Lets start with the enclosure Carr designed for the Atlas – he used a single billet of titanium and milled it in a way, that there will be no parallel or symmetric surfaces or structures anymore. The reason for this radical design approach is to reduce any resonances a cartridge body is prone to. Think about the fact, that just a very small percentage of mechanical energy a cartridge tracks, is converted into electrical energy which we can use with our phono stages and step up transformers. A cartridge is a very inefficient transducer. The major part of the sampled energy a cart gets from the record grooves is mechanical energy which resonates in the cartridge body itself and has to be directed in the most immediate way away from the stylus tip. If that is not implemented in the construction, those energy portions will interact with the tracking process itself, and we will hear a smeared sound, a sound with phase anomalies and distortion. Carr addressed both problems in his Atlas cartridge – he constructed the cartridge body in the bespoke new unsymmetric way, to avoid standing waves and resonances, and he developed a very efficient path to enable the implied mechanical energy to travel directly into the tonearm tube. To reach the latter, he uses a knife edge system in which the whole motor assembly is press fitted to the cartridge body, and to make the energy path even more efficient he constructed the most rigid contact principle in which a cart can be mounted to a headshell system of our tonearms. The Atlas SL gets in contact with the latter with a small surface area at the top of the cart, which is milled out of the solid titan billet used for the cart’s body. So the specific surface pressure is raised by a large margin with a given torque applied to the mounting bolds. Think of putting your hand under your girlfriends or wife’s feet, if she wears sneakers as opposed to high heels….it would make a tremendous difference…..you get it now ;-)))

The material titan is also part of the whole idea behind this cartridge, because titan is a lightweight but ultra dense and hard material. It is very capable of transmitting energy, and if it is used as Carr did with his Atlas cartridge – just one piece with all complex structures and form factors implied – you will get the most rigid construction with an amazing firmness to weight ratio.

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But Carr does not stop here….he implied a unique damper technology into the new generation of Lyra cartridges. The idea behind this unsymmetric damper technology is based on the precise observation of the coil placement in the magnetic field if we put vertical tracking force on the cartridge. Normally the coils will be deflected with vertical tracking force applied to the cartridge – so the angle between the coils and the magnet structure is not 0° anymore – we will loose efficiency and will gain phase anomalies. This is one of the reasons why cartridge manufacturers give us a certain maximum amount of VTF (vertical tracking force) – because of exactly this deflection angle.  In a traditional constructed cartridge we have to find the best compromise between tracking performance and vertical needle deflection – read magnet to coil angle. With the unsymmetrical damper the angle between the coils and the magnet structure is widened if the cart is lifted above the record – it looks weird if you see such a design for the fist time, because the needle looks in a way broken…..but it is not of course. If you put the needle slowly onto the record surface and observe this action with a magnifier you will realise that the needle together with the coils will be placed perfectly aligned if the correct amount of VTF is applied. Therefor the VTF “window” Lyra recommends is extremely narrow – so a good digital stylus gauge is a must have. And please measure the VTF at exactly the same height as the record surface will be. Dependent of the arm construction, you might face a huge difference if you put the stylus gauge just on top of your platter – or level it precisely beneath the platter at the exact same height as the record surface would be. As Lyra states in their technical specs of the Atlas, a VTF range of 1,65 – 1,75g with an optimum of 1,72g VTF  is recommended  –  you get an idea of the kind of precision we have to gain here! As the cartridge’s resolution is so unbelievably high, you will detect sound differences of every 0,2g more or less – so take your time and you will be rewarded with a perfect tracking performance and an amazingly balanced sound reproduction.

The  electrical “motor” of this high tech figment is also worth being explained, which brings me to the special magnet technology Jonathan Carr uses in the Lyra range since the Helikon / Titan I generation. In a more traditional cartridge we will find a magnet bar with a yoke system to distribute the magnetic field close to the coils. With this technology there is a certain amount of magnetic energy lost, because the magnetism must be transported via a yoke system. Lyra does that in a radically different way – they use ring magnets, which are positioned directly in front and at the back of the coils – it is a complete yokeless construction with a dramatical increase of efficiency. And of course the used magnets are the strongest neodynium types available today. Carr also modified the coil structure of the Atlas and also the Etna cartridge. Instead of a square piece of core which the coils are wound upon (soft iron), he uses a cross structure core. With the cross structure he gains channel separation better known as crosstalk between the two stereo channels. Carr uses 6n pure copper for the coils – as far as I know Lyra never chose silver – neither in their highly recommended cables (Lyra Phonopipe) nor in their cartridge designs. This fits my needs perfectly, because my amplifiers, preamps, phono stages and step up transformers are also built with highly pure copper implied, and I am not a big fan of mixing up different materials with electrical conductors trough out my system.

The needle Carr uses with the construction of the Lyra Atlas is made to his specific specs by the Japanese manufacturer Ogura. The term specific means a boron cantilever is coated with a very, very thin diamond surface. With this technology Carr achieves a material which is nearly as hard as a solid diamond needle that for example Koetsu offers to their customers as a special upgrade. But in comparison to a solid diamond cantilever the composite material chosen by Lyra offers less mass and a minimum of elasticity which reduces the danger of breaking the expensive thing. The cut of the stylus is a refined version of the line contact stylus shape, which is modified in a way that it builds a “long foot” shape which offers an exceptionally quiet tracking performance and a fantastic contact to the grooves – in other words, the Atlas tracks like very few other cartridges do, and it does it very, very quietly. Last but not least Jonathan Carr avoids any conductive material near the coil assembly to avoid stray fields and electrical interaction between his magnet / coils structure and parts that are not involved in the process of transferring mechanical into electrical energy. This is the reason why you will see a lot of specially made non conductive plastic materials used in the whole construction. It all starts with the green enclosure, in which the front ring magnet is housed and ends with the mounting plate, in which the rhodium plated contact pins are fitted.

Entering the SL….

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The standard Atlas version has an electrical output of 0,56mV combined with an internal impedance of 4.3Ohm. Since recently you can also order the Atlas in a special SL version – that stands for single layer, which addresses the amount of windings used on the coils of the cart. The Atlas standard has a dual layer coil structure were the SL uses just one layer of copper windings. This results in a serious reduction of electrical output (0,25mV) together with 1,52 Ohm internal impedance – and of course in a halved moved mass figure. Other than a standard Atlas cartridge which can be used with nearly any active phono stage, the SL version needs a very very quiet specimen – which is not easily achievable with a tubed RIAA stage – and also not an easy task if transistor technology is implied. So the Atlas SL is predestined to be used with a step up device in front of a high performance moving magnet phono stage. And as you can see in the technical specs I described above – we can use the same SUT, which fits an Ortofon SPU…..opposingly a standard Atlas likes to be mated with a 1:15 or maximum 1:20 step up transformer. A different, more exotic way to amplify such an ultra low output cart with its extremely low internal resistance is a phono stage that does not amplify voltage, instead the unit works as a current amplifier. Such devices work extremely well with low impedance carts, because Ohm’s law will tell you, that such cartridges are bad voltage suppliers – but good ones, if current is needed. My Air Tight ATE 2005 phono stage uses a current amplifier made with a Class A transistor topology as a head amp in front of the full tubed moving magnet RIAA stage – so I have two variants of amplification principles at my disposal.

Mounting and compatibility:

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A cartridge which is cultured around the idea of the fastest and most rigid mechanical energy transfer needs a tonearm that can handle all of this. At this point the tonearm – market is divided in different classes. We will find tonearms like the famous SME V, that represent a category in which the manufacturer uses an arm tube of a very rigid construction (one piece magnesium tube), but with less ability to absorb energy – instead the initiated energy will be reflected – something which counters the design principles of Lyra’s Jonathan Carr, who did everything to avoid exactly this scenario. The SME series V needs a cartridge mounted under its headshell system, which does help the arm with energy absorption – a Shelter Accord comes to mind, which uses 5 layers of carbon for the contact area between cartridge and the headshell system.  The SME V combined with a transducer like the Lyra Atlas will sound smeared with a treble section that is overly analytic, abrassive and nervous – the bass performance seems to be impressive at first glance – but if you analyse it more carefully, you will detect a lot of coloration and also some amount of distortion. This very famous tonearm was designed at the end of the eighties, it was designed with completely different cartridges in mind than a Lyra moving coil will represent now – so use these arms with what they are designed for. A SME series V combined with a Van den Hul Frog is a good match – to name just one example…..

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Another tonearm class might be able to handle the tremendous mechanical energy the Atlas cartridge sends into the armtube – but the bearings are not up to that task. Every little bearing shatter will now face a rigid transmission line to the needle (no armtube can dampen such a kind of energy) – and also vice versa. You will hear a thin, harsh and overly nervous sound reproduction.

You already got it – the kind of Formula 1 cart the Atlas is will expect a tonearm, which is constructed around Lyra’s core design principles. And as you also might expect – there are some designers on the market, who use Lyra carts to construct their equipment (amongst others), Alan Perkins of Spiral Groove / Immedia comes to mind, Frank Schröder, Bob Graham and Willi Bauer of Bauer Audio to name just a few! As you already know – I am a big fan of the Frank Schröder designs – and the Lyra Atlas allows me to explain one more time why this is the case…

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Frank uses special treated wooden armtubes – natural wood is a chaotic structured material which is nearly impossible to recreate using synthetic materials. God “constructed” wood with such a complex structure, from the molecular composition to its macro formation formed over millions of years, it is  a hard to beat material in terms of damping and energy absorption. But it has also a lot of disadvantages a designer must address. Wood reacts to climate changes, humid conditions, and wood has in its natural form a specific sound. Frank Schröder is surely the father of wooden tonearms which are prepared in such a way, that external conditions do not affect the material itself anymore – and at least as important – those armtubes lost their specific sound completely.  A very time and labour intensive treatment with different liquids like solvent, oils and coatings are used to fill up the kapillar structure of the wood. The different wood types Frank offers to his customers are justified to reach a specific effective mass. They are not meant to be musical instruments or tone controls, but the choice of certain wood types will let him build a tonearm with a specific effective mass without changing the basic material and its fantastic attributes. And of course – there is also the option, if more than one type of wood will fit the needs, that a customer can also change the look of his tonearm, which gives these arms a huge variation of different appearances. As every single arm is completely handmade by Frank himself and his trained hands – you will get a unique product. Frank’s legendary magnetic bearing tonearm will also imply other design aspects, which are very important if you think about a cartridge design like the Lyra carts. The magnetic bearing is completely free of any stiction, shatter and resistance – it is a bearing which is ingenious in its simplicity and execution. As Frank will offset the two magnets implied in this construction, there will be the possibility to dampen the  arm with the implementation of eddy current. The amount of damping can be widely adjusted by changing the size of the gap between those two magnets, which gives the user a tremendous flexibility, regarding the precise match of the tonearm, and a specific cartridge in terms of damping mechanical energy. In simpler words – these Schröder tonearms are a match made in heaven with the Lyra cartridge construction described above. Recently Frank has developed a new type of headshell plate that is made of a certain aluminium “foam”, which works as an energy barrier without applying any energy reflection. These headshell plates can increase the ability of his tonearms to deal with even more implied mechanical energy.

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To give you an idea about perfect energy transmission of a certain vinyl system – shut down your amplifier – put the needle down on the record surface and reduce the distance between the toneram and your ears….. do you hear some music??? We call that phenomen “needle talk” – an unmistakeable sign of energy which excites the tonearm and its mounting surface by the needle tracking the groove. The lower this “needle talk” phenomenon is, the better the amplified performance will be. If you get excited about what you will hear without any amplification and your toe is tapping with the groove of the unamplified music –  you should seriously rethink your cartridge – tonearm combination….

Adjustments:

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Such precise and in a certain form unforgiving carts like the Atlas SL need a lot of attention to detail while mounting and adjusting them into the tonearm. As the Atlas features a very sharp stylus cut – it tolerates no mistakes regarding proper geometrical allignment. A good template must be used, extra diligence will be necessary in adjusting the zenith of the geometry – small mistakes are not accepted by the stylus cut Lyra uses in its top class of cartridges. If you will detect, after some hours of playing time, that your brand new Atlas cartridge will collect a strange geryish dust around the cantilever and the white Japanese Washi paper which protects the whole motor assembly, you should re-check your alignment, because the dirt is vinyl dust – and you start to degenerate the quality of your records – as well as the cart itself.

The VTF was set at 1,74g, wich gave me the best tracking performance with a profund bass, with no compromised performance in the treble and air spectrum and also the micro dynamic skills the cart has to offer. The VTA was set level to the record surface with a 180g pressing, and was adjusted accordingly, if thinner records were used – normally I am not a VTA maniac – but the Atlas reacts very sensitive to this parameter. The Cartridge was mounted in my Schröder Reference SQ and also in the Schröder CB tonearm with usage of the standard Certal headshell plate and the newly developed aluminium “foam” plate. For amplification I used the Air Tight ATC1 HQ full function preamp with a MM gain of 43db and an Air Tight ATH2A step up transformer, which was set to its 1:30 ratio with results in 29db of gain, while the cartridge “sees” 52Ohm. The ATH2A uses Hashimoto HRX step up devices internally, which were a fantastic match with the Atlas SL cartridge. To compare the performance with and without a step up transformer, I also used my Air Tight ATE 2005 phono stage, with its current amplifying class A transistor head amp, that offered me 30db of tubed mm gain and 34db from the head amp system itself!

The SUT installation gave me a total gain of 72db while the active MC preamp of the ATE 2005 phono stage offered a total amount of 63db gain, which is on the low side of the scale, if a cartridge of less than 0,3mV is used. As the ATE 2005 is a very, very silent hybrid design, it was nevertheless a fantastic performance, that was slightly different than the sound of the SUT – MM combination.

The use of the new aluminium “foam” headshell plate of the Schröder tonearms raised the total performance in terms of stability of the reproduced stage and created a top end completely free of any grain or harsh artifacts – amazing!

If you use such a headshell plate together with Frank’s magnet bearing tonearms, you are able to raise the gap between the magnets a little bit more – without any sign of underdamping – which results in a more open performance with a tremendous quality of transient reproduction and tonal pureness!

The Sound:

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What struck me most in the first instance was the quietness in which the Lyra Atlas SL tracks the grooves. There is – a clean record provided – nearly no noise from the tracking process itself – the only thing you will hear is the tape hiss of strictly analogue recorded music without any noise reduction system like Dolby A or SR (recordings made before the mid seventies). The next thing that blows your mind is the tremendous, really shocking ability of this cart to start and stop with the flow of the music. This thing is so amazingly fast that my brain was often too slow ;-))) – It is as if someone connects you directly to the musical performance – a sort of direct to brain technology. And this is exactly what we will have if we listen to live music. There is no delay in reaction if you do not sit miles away from the sound source – the Atlas SL will place you in the first to third row of a concert hall. The rhythmic precision makes me speechless. drum attacks, piano, orchestra percussion, bass attacks and slaps – ohhhh….it is so unbelievably real, that it feels spooky in a certain way. The difference between the SL and normal carts from Lyra is profound. A standard Lyra lets the attack explode in front of you and is always better at the rendition of the leading edge than it is with the sustain of a tone – it excites you with a pure and tremendously precise rhythmical Gestalt of the music, but it suffers a little bit in showing the beauty of the tone itself. The SL version can deliver both – transients do not explode in such a dramatic and of course also very exciting way – they will be delivered softer in a very special manner. To understand that – let me give you an example. Imagine you are trying to cut your finger with a scalpel – you have to use a certain amount of pressure to make the blade split up your skin. The sharper the knive is – the less pressure is needed. Now lets change a very sharp scalpel to a device the biologist uses for microscopic preparation – a special tool called “Ultra Microtom” – this thing is able to split a sleeve of paper into 400 slices…..!!!! – And in such an “Ultra Microtome” way the Atlas SL shows us the attack – there is no pressure needed anymore – the performance comes as natural as breathing. It is so fast – even faster than the standard Atlas – that our ear does not get a form of energy conglomeration while reproducing an attack – there is no further energy needed – so the explosive character changes. And with that the balance of the reproduced sound changes too – because now attack and release have a tremendously natural relationship. The excitement while listening to such a very, very rare sort of performance with a cartridge results from the comparison to the real thing:

Our memory tells us what is real and what is a reproduction of reality – it does this with pictures, and also with sound. With the Atlas SL your special excitement comes from the fact that your memory is so loaded with all the extremely complex information collected during your whole life on how reality sounds in comparison to a reproduction, that your brain cannot devide between those memories and what you are hearing here and now.

I mean – this is really a glaring finding. A cartridge which is able  to fool our memory full of experiences of the real thing in terms of reproduction of attack and release of recorded tones, so much so that we cannot differentiate anymore – wether we are hearing a real performance or a recorded one (a good recording is of course mandatory) – this is a gift we have to send a BIG THANK YOU to Jonathan Carr and the whole Lyra team!!!

The Atlas SL does not stop to impress me with its performance of attack and release or sustain of music – there is much more – MUCH MORE!!!!

The cartridge gives us a sort of unforced resolution that is astonishing. You can differentiate the violins from the violas and those are perfectly seperated from the celli – a sort of phenomenon you can only have in very good concert halls like the Berliner Philharmonie, if you sit close to the sweet spot of the orchestra. You can follow the musical performance with the score placed on your knees and listen while reading the accolades, enjoying a spectacular ride through the micro-structures of a composition. But you can also relax, sit back and listen to the whole beauty of the music – the cart enables you to zoom in and out whenever you like – an educated way of listening is not necessary – it can be done by everyone! It is a sort of resolution that frees up our brains while listening – less work has to be done by your brain to correct things you hear, which do not fit in your tonal memory. The space around the different instruments and instrument sections, the kind of resolution between a note and silence is spooky. You can get deep enjoyment while listening to the most complex music – because it is not a dense wall of sound anymore, it is an organised and perfectly arranged composition – there is not the slightest sign of compression or stress in such passages – the Atlas SL sails through the most demanding passages with an ease and gracefulness it is hard to describe. The pin point accuracy is even more spectacular – the instruments of an orchestra, the vocalist and even synthetic instruments are placed, if the sound engineer does not change his panorama position, as if they are nailed on their position. The phase coherency is outstanding, which makes the whole Gestalt of the music so real and great!

To give you a picture for a better understanding – which brings me to the title of this essay – the Lyra Atlas SL behaves like a Shaolin fighter. Complete mental strength, absolute precision and discipline together with a tremendous speed of motion and power our eyes (read ears) can hardly follow – combined with a graceful Gestalt – that is what the Atlas SL is all about. The cart sacrifices its character to support what it is made for – to bring music to life! This is an exceptional gesture which divides the absolute top class of cartridges from the lesser ones – and the Atlas SL stands out even at the zenith of what is possible with a needle tracking a record groove today!

It is obvious that the Lyra has a very balanced performance in terms of frequency reproduction. The very, very important mid band is as liquid and neutral as it can be. There is not the slightest coloration detectable – well done!!!!

The bass performance waived every little touch of being more impressive than it is captured in the microgrooves of our records. No slight low mid or upper bass bump, no deep bass augmentation – nothing. Instead of this, the extension in the bass spectrum is without any limits – the bass itself is ultra fast and articulated – the tonal substance is frightening and – yes I know it is boring – it sounds sooooo REAL!

Presence and treble both need some explanation – gone are the times were a Lyra top performance cart was a little bit over the top in the higher and highest frequency range – now we face a neutral tuning of the presence and treble region, which is not muted or damped or rolled off. The modern Lyra carts get their treble excitement from dynamic resolution and the ability to render a tonal substance even at those frequency-extremes. A cymbal is never an acoustic event like white noise, instead of that you get a very, very fine detailed picture of what and how the drummer is playing on his ride cymbal – frighteningly REAL.

Step up transformer or active gain stage??

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With the use of a step up transformer the Atlas SL gains a little bit more a holistic expression, the treble and air range is more integrated as is the midrange, which is also perfectly linked up to the presence and treble section of the spectrum. The whole picture is a tiny, tiny little bit warmed up. The ability to render recorded space is astonishing and there is not much on the market that could do this better – than a good transformer combined with an Atlas SL. The expanded rendering of the acoustics of an orchestra hall is done in a style that you close your eyes – and there seem to be no walls in your room anymore. Sometimes little details come from angles were no speaker is placed, and you get goosebumps…. It is also possible, that you think someone entered your room or flat – more than once I dropped the volume and asked my wife if she is back from work – but there was no answer – and I was alone with my Lyra Atlas and my record… Small details are rendered in such a realistic way that your brain is often not able to realize if it is coming from your record or if it is generated in your room by someone else – spooky – but GREAT!

When I use the active head amp of my ATE 2005 phono stage the picture gets a little bit different. Now the Atlas SL shows a more neutral character with some more sparkle on top and maybe also a little bit better dynamic range, especially in the deepest bass regions – but less good micro dynamic Gestalt. The big swings are reproduced in a more spectacular way, just like the pinpoint accuracy and the space between the instruments. But the ATE 2005 lacks slightly the holistic performance of the step up transformer. The performance is more savoured in an intellectual way, while the step up transformer will give you a little bit more the heart and soul of the musical performance.
With Singer Songwriter and Classical music – as also Jazz I would prefer the combination with a step up transformer – if you listen to Electro, like Kraftwerk, Trentemöller or James Blake, the ATE 2005 will be my phono preamp of choice, the more accurate and slightly shinier performance fits the needs of such music perfectly as does the spectacular bass performance.

Some people could miss the analogue warmth in the presentation of the Lyra Atlas – its neutral Gestalt and the ability to disappear as a transducer might not fit the bill off everyone. It is not the analogue sound you might know or adore, it is something new, something really outstanding, that we have to get used to. The Atlas SL is not fighting against other cartridges anymore – it defines a new chapter in analogue reproduction, which can compete with any new media, be it high resolution digital streaming machines or the last development in sound reproduction technology itself. It is not about being the best cartridge in the world it is about making a statement in terms of music reproduction in general. It is as close to the mastertape as I have ever heard it from a cartridge!

If you want to have more analogue Gestalt, more sexy midband performance, maybe more texture in this frequency region, and if you miss some of the so exciting punchy bass hits – than Lyra has also something for you. No – I do not mean the Lyra Olympos, which starts a whole new chapter with Lyra transducers, and is for a large group of Lyra fans the best cart they ever brought to the market till today (if you could get your hands on a donor Parnassus and its platinum magnets). Jonathan Carr realised the euphoric reaction to the Olympos – and he apparently knows how to dial in some different sound aesthetics in his products (an ability I admire!!!) – so he finished his 5th Generation of Lyra transducers with the successor of the famous Lyra Titan, which is named after the legendary Sicilian volcano Etna! – I think you already got it….I mean if Carr is using this name for a cartridge – it might give us an idea, what he had in mind….and the best news for us Lyra devotees – also the Etna is brought out in a single layer version – the Etna SL.

But that is another story for another day…..

 

Stay tuned

 

E. Strauss

 

 

 

The Marantz CD94 – Part1 (the drive mechanism)

A musical digital player??

If we look at the CD player situation today, there is not much to write home about…. Today we have to accept, that nearly no company is manufacturing dedicated CD transports anymore. The last decade was full of CD machines which used transports originally deigned for computers or car stereo systems – the decade of really high quality dedicated CD drive mechanisms ended around the the year 2000. Since than we got a lot less for a lot more money. Any DA converter needs a proper source, and if  we skip for a moment the whole streaming possibilities, the source for a DA converter is a sort of physical media – normally a CD or a SACD. Both optical media needs a damn good drive mechanism for reading the implemented digital data – hopefully with near to no loss, low jitter, fast and secure action, isolated from vibration implemented by the player itself or from the outer world.

Maybe you asked yourself while reading CD player offerings at the used market – why in nearly every advert you will see, there is some information written about new laser mechanisms or a brad new complete CD drive which was implied in a 4 year old machine??

Now lets jump directly to the years from 1985 – 93….the time, were you sold your record player and dived into the modern digital world. You bought your first CD player – and you had during its time in your HiFi system never any problems with the CD drive mechanism – maybe the unit needed at some stage a new driving belt for the CD drawer – but changing laser mechanisms or whole drives was not a task you had to deal with – right????

You changed in that period of time maybe the player – maybe more than once, because the big HiFi magazines told you that every new generation of CD players surpasses the actual generation – so an upgrade was mandatory….  The same story is also told to us till the CD as a mass media lost its importance agains streaming solutions. But was it really true, what was proclaimed???

Philips changed the design of their CD 0 drive to the CD 1 and later on they brought out the CD9 and all these steps were not made to design something better – it was made, because they wanted to make the things cheaper. The same can be said also about the ladder multibit DAC – in Part II of this article I will come back to that story.

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Believe it or not – one of the best transports ever made was the Philips CDM 1 pro drive used in the end of the 80ties, last century – and even the first CD transport ever manufactured, the CDM 0 was a legend, regarding data integrity and fast operation. Those CDM1 pro drive mechanisms were used in the CD check machines the mastering studios used to check the digital quality of the media (digital errors). They were so good, that it was the reference, were everything else was measured against it. And of course they were expensive – made from metal cast, supplied with a sub chassis mechanism, a Rodenstock glass lens system (no plastic optics) and the speed of tracking though the index of any given CD was miles ahead of nearly anything which came later to this party. In one word – it was maybe the epitome of a CD drive mechanism – but it was too expensive to achieve a complete player, which could compete with the price of a cheap coffe – machine at the point of sale – electronic super markets…. From that time on, things got not better regarding the CD drive quality – it got worse – and today we have to accept, that in most modern CD players we will find just crap, which has to do the sensitive job of reading data from a digital media!

What really changed during all this years is maybe the quality of the DA converters – in the 80ties more that 16 bit resolution was seldom seen – and at the end of the ladder DAC period, 20bit performance was the best we could achieve with this technology. However – if we do not get the data from the media with the highest possible integrity and precision – if our source is not of the highest quality – all which comes in the signal chain after that stage is more or less questionable.

Restauration of a masterpiece:

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The CDM 1 Pro drive used in one of the most well regarded CD players during those years, the Marantz CD94 (and also the MK II version of this player) will have some problems because of its long period of usage, we have to care about. Most of the units which are offered as defective, do not have any trouble with the laser diode – they all share one design problem, which we have to deal with. This design “problem” addresses the bearing of the rotary CD platter. This bearing is constructed as a plain bearing – a spindle is placed on a special plastic disc – the plastic is of such a kind, that the spindle do not need any excessive lubrication. Over the years this spindle works now its way into the plastic platter – there will be at any CDM1 pro a more or less deep groove in this plastic platter of the main drive bearing.

If the groove is cut very deeply, the distance between the CD surface and the movable laser diode is at some point too large – so the laser unit can not precisely focus anymore. The player will give us some error message – and most of the users think – the laser diode is worn out – but in most of the cases it is just a mechanical bearing problem . To solve that, we have to adjust the platter hight to a point were we compensate for the groove. This is manageable with a little bit of technical skills and a service manual developed for the specific player and its Philips drive mechanism. If we adjust the spindle height to a level, were the two axis element of our laser mechanism is positioned in its neutral level again – we are done. Of course one day the plastic disc of the bearing will be completely worn out – and there is no chance to get a replacement part as far as I know – but I can assure you – the mechanism will work for another 15 years from now on – if we do not use the player as a burn in device – playing in continuously repeat mode for weeks or months;:)) In the service manual we will find a certain voltage and the points were we can measure it to adjust the platter hight – for that procedure a perfectly flat CD has to be used with some test signals on it (CD/R made by yourself). All in all, if you know how the procedere works, it is a job done in 20minutes. If you do a good cleaning (highly recommended), the whole work will need a little bit longer.

Recap:

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Another thing we have to deal with are all the electrolytics used in the player – not only in the drive compartment – I mean all the electrolytics, this is a job done with a lot of care and some patience. Today we have some great opportunities with modern designed caps. The SANYO OSCON electrolytics have a very temperature independent behaviour which is a very good thing with all the digital circuits and the drive mechanism. At other stages we can decide to use caps which we like because we think they give the unit a specific sound (Black Gates, Elna…) – and of  course we have the amazing Panasonic FC cabs, which is a strong recommendation for the power supply decoupling.

Sound experience:

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After the complete recap, we will be stunned, how such an old device will sound. The Marantz CD94 has maybe one of the smoothest treble performances of all CD players I know of – it is the opposite of what we will find in most modern players – the treble has a sort of creamy gestalt! This could be a good thing – because of 100 CD´s 98 are mastered with a very hot or aggressive treble – a circumstance which seems to characterise the digital sound, but which is more or less also a problem of the software itself. To explain this more in depth, I have to dig a little bit deeper – we have to talk about production techniques in the recording stage, mixing and mastering process. If you compare a modern digital workstation as AVID Pro Tool against a 24  Track 2″ tape recorder there is a huge difference – not only in the native sound of both units – more so in the style you are able to use them. With an analog recorder we have a certain limit with the frequency extremes. We cannot put the same amount of level on the tape in the extreme bass region as also in the treble region compared to the whole midband. If we do so – the tape machine has a surprise for us – or better two of them – noise or distortion. Lets say for a moment we want to produce a Hi Hat – and we want to have a sound with the highest amount of shimmer we can afford, there is a special technique to reach that. If we would put some EQ on the Hi Hat off the tape – after we already recorded that signal, we will boost tape hiss…. – if we put all the EQ to the Hi Hat before we record it – we will be punished with less gain possible to put on the tape – otherwise the signal will be distorted – and the result will be distortion or again tape hiss. So a mixture of both techniques is the goal – a little bit emphasis befor the signal hits the tape – and a little bit in the mix, were the signal comes off the tape. The keyword here is LITTLE!. In the digital world there is not such a limit…I am technically able to put 12db boost on a Hi Hat at about 12Khz – and there is no other punishment as my bleeding ears. Which brings me to the essence of that little example….if we engineers have no technical limits, it is up to us to decide what sounds good and what sounds bad. And with too much freedom, we will face a great risk to overdue it….In other words the analogue tape recorder is one of the biggest teachers for us recording engineers in the control room. Their limits give us a sort of certainty, which we all lost with the digital age! If you are sitting 10 hours or more behind the console, you loose the ability to judge the sound – but in the analogue domain we had some security implemented into the whole system, with digital everything is possible. And this is in my opinion one of the reasons, why with the upcoming digital technologie, we miss more and more a sort of natural sound – because all is possible and often some more treble in the mix seems to be more exciting….

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Now lets talk about the relationship between the producer, the artist and the recording engineer. It is a customer relationship – the producer wants a sound which competes with an international standard, the band wants a sound which is impressive and supports the idea of the song. Later on the mixing engineer will do the final work on a multi track session, often with more than 80 audio tracks implemented into the mix. Again the band and the producer wants to have the nearly finished product to be better than the reference recordings played back and forth during the mixing process. It has to be loud, powerful and impressive. So the mixing engineer will put a good amount of compression to the mix, as also a lot of EQ to make 80 tracks compatible to work with the basic idea of the song (a disaster!!!). Later on in the production process, the song hits a mastering studio – and again we have a customer relationship – the mastering engineer must bring the mix to a higher level – it is not “en vogue” to master the stuff in a natural way – it has to be louder than other comparable productions, it has to compete with the loudest tracks broadcasted at the radio. If the mastering engineer switches the mix file against the mastered version, all listeners in the mastering studio wanted to have this magic thrill – “Oh my gosh…..this sounds sooooo impressive”.

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At the end of that story we will have some music mastered on the CD which has at best 8db dynamic and we will face a frequency spectrum which boosts the extremes – a lot of shimmer, plenty of bass and a down shaped mid frequency spectrum – some tricks at the Flatcher/Munson frequencies and finished is another song which works perfectly in a car stereo system while driving on a highway at high speed – but listened to a good High End stereo system, we get bleeding ears – the music is boring – because no dynamic shades are anymore detectable – and we think – “Fuck digital”….but it is not the digital technology itself – it is the way we work with all the possibilities. If you have a chance to listen to Radiohead “In Rainbows” (for example) on CD, you will hear that it is possible to achieve something great, something outstanding even pressed on a CD, there is nearly no difference between the vinyl edition and the CD – and yes this album was recorded with an analogue tape machine…

Using the CD 94 as a dedicated drive:

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Coming back to the drive mechanism of the Marantz CD94 it is obvious, that this old machine will be a very good CD drive, maybe one of the best regardless of its price. If you want to skip the legendary DA converter implemented in this player – developed around one, if not the best 16bit ladder DAC the Philips TDA 1541chip set – you are in for a big surprise. But before “happy listening” we have to deal with the digital SPDIF (Sony – Philips – Digital – InterFace) interface which the engineers at Marantz implemented in this player to be able to communicate with external DA converters. You will detect a RCA jack at the back of the player – a thing, which most of the CD players have in common, regarding a SPDIF digital output. But this “standard” is wrong – completely wrong – because the SPDIF technology wants to “see” a proper 75 Ohm wave impedance. No RCA jack can deliver the proper specs implied in that technical standard – so we have to change the RCA connection to a proper BNC socket. And if we do that, we have to dig a little bit deeper. The Marantz CD 94 in it´s standard original configuration, gets its SPDIF signal from the Philips SAA 7220 digital Filter chip. The SPDIF signal is carried with the corresponding conductor path on the right hand side (mounted at the side of the chassis) daughter board and is further distributed by some connectors and cheap cabeling. So it is a good idea to grab the signal directly from the 7220 and use a dedicated 75 Ohm data-path together with a small circuit board, which brings the signal to the correct SPDIF specs – +/-0,5V and 75 Ohm wave impedance. Finally we feed the signal in our BNC connector and achieved a perfect SPDIF interface.

More modding:

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If you have tasted some blood now – there is even more, you can modify to reach the best performance – even if you just use the Marantz 94 as a dedicated CD drive. The Philips SAA 7220 is the biggest problem in the whole surrounding of the TDA 1541 DA converter and its signal flow. The reason for this is the HF dirt this chip delivers into the circuits of the whole player – this is more important if you use the player as a full function CD player – but also of some interests if you use just the drive mechanism. The Marantz CD94 was built at a much bigger budget, than one might think – but at some stage Philips/Marantz hat to cut down costs, because they wanted te player to be placed at the lower end of the High End player segment. At some parts of the player Marantz decided to drop the best solutions which were technical possible. One of this cut down areas is the power supply as also the delivery of the voltages to the different sections of that player.

First of all, the Marantz has just one power supply implemented – there is no seperation between digital circuits and analogue sections, as we will find them in Accuphase CD players of the same aera  (they were of course much more expensive). Accuphase used from the beginning of their CD player development on, always two separated power supplies, which facilitates them to isolate the digital path completely from the analogue path. Marantz opted for just one power tranformer / power supply. Why do we not modify an Accuphase player than??? – Because Accuphase used a Sony drive mechanism in those years and there is no hope to get any spare part for them anymore – and if we want to buy another player as a donor – the whole story would be very expensive – and last but not least – as good as the Sony drive mechanisms were, they found their master in the Philips CDM1 pro.

So we have to deal with the power distribution inside the Marantz CD 94. Our goal is to isolate as much as possible the SAA7220 from the rest of the player – to achieve that, we have to construct a dedicated rail only used by this chip. And if you are dealing with such an idea – built more than that single voltage regulator – because I know, that after reading Part II of this article, were I will dig deeper into the DA converter of this machine, you will use the Marantz not only as a very, very good CD drive…..;-)))

The original voltage regulators are placed at the heatsink, you will find on any TDA 1541 player, be it a Marantz, a Philips, Rotel, Naim and so on…. Now you know, why these players all share the same strange heat sink at the rear side of their chassis. The original player uses 3 regulators with this heat sink together – and we put another three into this machine. This gives us enough flexibility to modify also the analogue section of this player – but more important to give the SAA7229 beast its own rail with discrete voltage regulation.

The marriage with a high performance DA converter:

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If you use the Marantz CD 94 drive with an outboard DA converter using our modified SPDIF interface, you also have to get a proper SPDIF cable. It is not recommended to use a normal NF cable, which you normally use between your preamplifier and power amplifier – because a dedicated SPDIF cable has to be made with the 75 Ohm standard in mind. A very, very good choice is one of Chris Somovigos digital cables, he developed exactly for that purpose. In other words – this is one of the best options I know of. Be it a Stereovox, Stereolab or Black Cat 75 Ohm SPDIF cable – all are super performers – and you do not have to spent more money to achieve a better quality – these cables are of the highest class!

Now you have the choice to choose a DA converter you may have on top of your wish list. You can buy the newest and hottest stuff available to get the best of two worlds – the best drive mechanism ever made AND a ultra modern High End DA converter. One of the most exciting combinations will be a DCS Paganini if your speakers and the whole system is very neutral and not overly analytic. This combination is soooo good, that you will forget to play vinyl records for a long period of time. The combination is much better, than the integrated DCS Puccini CD/SACD player. The Marantz – do not ask me why, has a certain smooth sound, even if you use just the drive mechanism of the complete player. The sound of the drive is so grain free and elaborated at the treble spectrum – it is amazing – together with a very, very high resolution converter as the DCS Paganini is, you will get something which is hard to describe. If I have to characterise this specific digital sound to a moving coil cartridge, I would choose the Lyra Etna SL as an analogue opponent. A frightening resolution paired with a smoothness (used in a proper tonearm with a high quality SUT) and velvety gesture is apparent, a pinpoint accuracy which let you breathe the atmosphere of the recording event – fantastic!

If you use a pair of the legendary BBC LS3/5a monitors, the combination of the Marantz CD 94 drive with a DCS Paganini is not the best option. The LS3/5a has a slight treble rise – it is in that discipline the opposite to a well placed and integrated Quad ESL 57, which acts a little bit defensive at the highest frequency spectrum.  With the use of the BBC monitors a non oversampling tube DAC would be my first choice. And one of the finest options with a lot less money to spent as with the super expensive DCS stuff, will be the German manufacturer Acousticplan. The Digi Master  Tube DA – converter is a hell of a machine!!! If i should compare this combination with the analogue world of cartridges and turntables – I would go for the gestalt of a very nice Koetsu Rosewood Signature cart. A slightly recessed treble paired with a good punchy bass and the ability to layer the recorded space in a more integrated style. This combination is not analytic, it is about the tone, the beauty of the midband and the wholeness of the musical performance.

Stay tuned – part II of the Marantz CD 94 will come soon.

E. Strauss

The famous 6L6 GC Powertube

The forgotten tube

If we analyse the HiFi market today, searching for an amplifier witch is constructed around the 6L6 GC penthode, we have to face the fact that there is near to nothing on offer. In the opinion of many HiFi and High End enthusiasts this tube is made for musicians and their guitar amplifiers – not good enough for serious listening purposes.

This is completely wrong!

Some of the most respected Mcintosh tube amplifiers used the 6L6 GC, the amazing Mc30 monoblocks come to mind or the Mc240 stereo amplifier. The 6L6 GC has one great advantage compared to KT66 or KT88 as also EL 34, you can get new old stock quality without searching for months and spending crazy sums. The supply will vanish in the next couple of years but here and now there is still a great chance to get a matched quad of nice vintage 6L6 GC tubes.

The 6L6 has a very long history till it reached its last incarnation the GC variant, which is the most powerful example of them all. The tube was originally made for military applications and for that reason it is a very robust kind of a tube, the construction had to withstand a lot more when used in applications of the US Air Force, as we would ever could think of in our music reproduction systems. There is a good chance that a vintage set of well matched 6L6 GC (NOS) will work for many, many years of regular use in your power amplifier without the need to be replaced.
Something modern tubes from China or Russia can only dream of.

The Air Tight ATM4:

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But all that is worthless if you won´t find a good amplifier to put the fine glass into it. One of the rare examples of exceptional modern built tube amplifiers constructed arround the famous 6L6 GC or one of their equivalent the 5881 will be the Air Tight ATM4 manufactured by the small Japanese company A&M Ltd. The founder of this company Atsushi Miura was born into the audio industry, because his father, who begun to wound transformers for the Japanese audio industry back in the 30ties of the last century, became the head of the Luxman Cooperation, a brand name well respected in the history of HiFi or High End. Under his fathers guidance, Miura made his way through the company and ended up as an audio designer, who was responsible for some of the most famous tube amps this company had to offer. Miura learned the “art of audio” from the ground up, and took over the reins at Luxman. In the 80ties the company was sold to the Alpine cooperation with now biasing towards the more commercial aspects of that industry, something which Miura san was not intended to tolerate, so he left Luxman and founded his own brand, A&M LTD, with the brand Air Tight and Acoustic Masterpiece.

A living legend:

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Miura san is one of the last living legends in the famous Japanese tube scene today, which had to suffer so many losses in the last couple of years, the passing of Kondo San as also Shindo San comes to mind. Very sad news for those of us, who want to enjoy a classic tube amplifier with that typical Japanese attention to detail and therefor a sound characteristic, which is hard to describe. Those amplifiers are maybe not the last word in neutral music reproduction, but they can deliver a sound which becomes a sort of hyper realistic picture of real music played by real musicians. Very often you can forget with these amplifiers from Kondo, Shindo or Miura San (Air Tight), that you are listening to your HiFi setup, and not to a real performance. They share all in a different way the same goal – you should relax and you should be able to take the musical performance reproduced from a vinyl record or CD for something real. To reach such a goal, there are some tricks, these old Japanese masters put into their “music machines”.
It could be a very common practice, that such an amplifier will bei the last one in your live – forgotten is all the technical stuff, all the technical reference data delivered by the most famous High End companies today – instead you get something very seldom found in the enthusiastic HiFi scene – you get satisfaction.
No “upgraditis” anymore – you relax and you start to enjoy music – instead of that typical self-questioning – is there maybe too less air around the cymbals ? – could the singer maybe need some more sparcle at the top end? – is the bass dry enough – and is it deep an powerful enough?….all that comes to a sudden end and you will listen to music.

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The ATM4 form Air Tight will remind you from its outward look to some designs made in the 60ties (last century), the Marantz 9 monoblocks comes to mind. It is an amplifier with no exposed tupes, which could be a good thing if you have pets or little children…..

A very classic no nonsense design which takes his beauty out of a puristic “form follows function” appearance.
The front plate is dominated by a round bias meter (a quote from the Marantz 9), which shows the bias (DC) balance between the two pairs of output tubes. Under a screwed-in plate you will find the corresponding bias – balance potentiometers. In normal use this potentiometers are covered by the bespoke aluminium plate with the engraved manufacturers name. Left of this plate we will find an input switch, the ATM4 comes as most of the Air Tight amplifiers with two sets of line input terminals. If you just want to use two sources with these amplifiers, they could be used as a very puristic integrated amplifier. On the right hand side of this input switch we will detect two input gain potentiometers. Use them to adjust the power amplifier in terms of gain, to match the characteristic of your preamplifier – and you are also able to use this feature to match the whole amplification system to a cartridge with very high output (EMT JSD series) or just the opposite – a cart with extremely low output (AN IO for example).
The potentiometers are hand selected Alps Japan Blue Valvet potis, which are high quality parts – so there is no need to get rid of them, they are acoustically invisible, a precise gain matching feature ist worth to keep them in the signal flow!!! The second pair of input jacks could be also used together with a CD player or DA converter with adjustable volume on board. In such a case, you can skip the line preamplifier and connect the digital device directly to the power amplifier.

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On the right side of the amplifier we will find the bias switch, which is used to select the two pairs of tubes displayed on the bias meter. And of course there is also an on and off switch.
The rear panel is fitted with 2 pairs of RCA input jacks, and 2 speaker terminals with the possibility to configure two impedance settings. The factory standard is a 4 and 8 Ohm tap, which could be also configured internal to 8 and 16 Ohm. Last but not least we will find the IEC power socket for a dedicated power outlet cable.

Tube rolling:

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If we unscrew the top cover of that amplifier, we will see a special feature – the Air Tight ATM4 is able to be comfigured as a monoblock amp (we will need two of them in this case) or in stereo operation mode. For the Mono conversion we have a toggle switch together with a switching knob both lettered with Mono or Stereo – keep in mind – usage of these switches wil presume to shut down the amplifier first.

In Mono operation mode the output power is doubled, so the ATM4 is able to handle even more complex loads.
The tubes implied under the top cover are:
4X 6L6 GC or 5881
2X 6CG7
1X 12AT7 /ECC81

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It is a classic Mullard design layout were the splitter tubes (6CG7) are also used in the driver stage.
The one and only line level gain stage is accomplished by a single 12AT7 double triode, which gives us an input sensitivity of 1,5V, that means you need 1,5V to modulate the amp to its maximum output power, which reaches its maximum at 2X 24W in Stereo Mode or 2X 48W in Mono operation.
If we compare this figure with the famous Mcintosh MC40 amplifier, we have to consider, that the MAC has a maximum output power of nearly 2X 40 watts with the same output tube compartment.
Miura San opted with his design for a higher damping factor to handle more complex loads, for that purpose he used no global feedback but a good amount of local feedback implied into the ATM4 amplifier which results in  a very good “drivability”.
In other words – the ATM4 ist designed with electrostatic speakers in mind, like the Quad ESL 57 or the ESL 63 for example.
The ESL 57 needs just around 15 – 20 Watts to reach its maximum sound-pressure level – but it is everything else than an easy load.
Please read my article about the Quad ESL 57 Quad ESL57, for the closest approach to the original sound. Part 1 you will get much more information about that topic.
One of the most asked questions regarding the famous british electrostatics would be the question, “which amp is able to drive them whith ease an precision?” – the ATM4 will be one possible answer to that question.
And it is a much, much better choice as the original Quad II monoblocks designed together with the ESL 57.

Signal flow and design:

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With the 6L6 GC we will face two very famous specimen of this famous output tube, the RCA 6L6 GC Black Plates and the General Electric 6L6 GC Grey Plates, double side getter.
Both are very good choices to get one of the finest 6L6GC ever made.
If we listen to the basic sound of the Air Tight, which is very, very transparent and open, I would give the General Electric 6L6 a slight advantage in terms of smoothness and a grain free treble.
The RCA variant is much more “zippy” on top, which does not correspond as good as the GE6L6 to the basic sound of the ATM4.
One of the reasons for that openess and transparency might be the legendary output transformers from the Japanese manufacturer Tamura.
Those output trannies are one of the finest options available today – and are broadly used in the Air Tight portfolio. Another amazing power tube option could  be also  the Tung Sol 5881 – the tube might look small from its appearance – but the sound is  big and bolt with a smooth sparkle on top, which Tung Sol also implied in its very famous 6550 black plates.
With the splitter /driver stage, we have to find a tube, which has an equally good performance in both stages.
There are two very good options for this tube position – one option will be the RCA 6CG7 clear top, and the other one is the Sylvania 6CG7 metal shield grey plates. The RCA clear top gives us a more sophisticated treble, there is more resolution in this frequency range and a very good ability to render recorded space. If you choose the GE 6L6 GC output tubes this will be a fantastic match. If you choose the RCA Black Plates 6L6 GC the Sylvania 6CG7 might be the better option.
The last tube we haven´t spoken about till now is the 12AT7, which represents the input gain section. This is not such an easy task as it seems to be. To get the most out of this tube position, I have to give some more detailed descriptions about this tube and the problem to find one, which fits our needs in this amplifier.

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If you think about the 12AT7 you can basically divide the whole bunch of them in two sections. One category is more suitable if the 12AT7 will be used as a driver stage, such design we will find in new Mcintosh amplifiers like the MC 275 MK IV – VI.
Mcintosh skipped the utilisation of the 12BH7 which was originally used in the old vintage MC 275 as a driver tube for the KT88 and replaced it with 12AT7 in this stage.
12AT7 tubes which are very good at this specific task are the US made types such as RCA 12AT7 black plates, Sylvania gold brand black blates or Tung Sol 12AT7 black plates.
If you use one of them in an input stage of your amplifier or preamplifier, you are in for a big surprise – gone is the ability to render a wide soundstage or the ability to place sound sources in front of the speakers or behind them. The whole spatial performance will be negatively affected.
Also the treble performance and the resoulution are very restricted – in one word – it sounds bad – really bad! – But if you use one of those famous US tubes in a driver stage, it is an amzingly good choice – maybe one of the best you can get. This is one good example for the importance to know which job in a given circuit a specific tube has to do and  why the opinions about the quality of such a tube differ so much.
One person tells you a black plates RCA 12AT7 is heaven on earth – and the next calls it crap…..
This makes us aware, that we alway have to tell the people in which part of the signal chain in an amplifier we listen to a specific tube – because the conditions in different stages of an amplifier are very specific – and the same tube could be bad in one stage and shines in another.
With the Air Tight ATM4 we can nearly skip any US 12AT7 the only exception is the Sylvania gold brand, black plates 12AT7 which is a good performer.
If we dig deeper, we face now the whole European ECC81 elite at our disposal.
But it is also not an easy task to get the right tone out of these ECC81 –  at the end it is one of the most complicated tubes to roll.

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Mullard had just one very good ECC81 it is portfolio –  the very old dark grey (nearly black) plates design with 3 round side holes (plate construction) made between 1955 – 1958 – and those are rarely seen today in the used market. And this Mullard ECC81 might be very good – but its sound is too polite in the treble area to work well in our Air Tight ATM4.
The exact opposite direction will be adopted by the Siemens Halske E81CC double getter support, triple mica – this is one of the most analytic ECC81 and also one of the most dynamic tubes in its class….
But – you guess it already – it is too much for what an Air Tight ATM4 might need!
There are some rare variants which can sound outstanding but in spite of hunderets of different well made ECC81 just a few options are really outstanding with this amplifier.Lets start with the cream of the crop….this might be an expensive option, and it is also a very, very rare tube – but the Valvo Hamburg made 6201 blue print, gold pin, pinch waist is a hell of an ECC81 tube!!!
Maybe this is the best or one of the best ECC81 I ever listened in an input or gain stage of an amplifier or preamplifier.
It has it all – resolution, dynamic, deeb and articulated bass, a very sophisticated treble without being too analytic, an amazing spatial sound and more so – unique qualities in the department of rendering micro dynamics and inner detail which is hard to beat!
But this little “super hero” is sooooo rare and sooo expensive – that I will give you also more common alternatives – but if you want the best – the Valvo will be my first choice!
The second best is also not very common – it is the same Valvo described above but without the pinch waist glass structure.
Beneath these exotic tubes it is also a fantastic idea to use a Telefunken ECC81.
If you can find the first series with the slanted O getter, it will be a very good choice, as it will be the Amperex Bugle Boy /Philips ECC81 with the large O getter.

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Coming back to another output tube option – the tung Sol 5881 will be a very good alternative to the 6L6 GC from General Electric. The Tung Sol will deliver a warmer tone with a unique character in the upper midrange – I would call this characteristic somewhat a creamy presence with a colourful and complex sound character. The Tung Sol 5881 might be not as common as the 6L6 GC – but it is worth to search for it. Do not be surprised, if the appearance of this tube might differ somewhat from the picture above, this tube came with a large variation of base colours, and also the mica clips at the side changed over the years.

How does it sound??

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The Air Tight ATM4 will give you with the following tube setting a sound quality, which is completely amazing:
4X General Electric 6L6 GC double side getter, grey plates
2X RCA 6CG7 clear top
1X Valvo 6201 blue print, gold pins (pinch waist) or Telefunken ECC81 slanted O getter.

It will perform in such a powerful way in spite of its apparent restricted output power of “just” 24 watts per channel, that you will be stunned.
Be it the Quad ESL 57, a pair of BBC LS3/5a or some 12 or 15″ classic Tannoy with Alnico drivers, the ATM4 will handle them all with great easy and with a sound quality normally not associated with the 6L6 GC power tube!
The sound is very controlled, slightly on the analytical side of neutral, you will never think of an overly warm and rose tinted tube amp – instead you get tremendous speed and accuracy.
The bass is immensely fast and articulated, and without the slightest emphasis on the upper bass region so many tube amplifiers could be characterised of . It is a bass performance a lot of very sophisticated transistor designs would be proud of.
In the midband there is this difficult to describe miracle happening, a kind of “being there” – sound, a floating midband, which is as natural as breathing. The treble has some seldom heard three dimensional characteristics with a very rich palette of different colours.
The resolution is mind blowing and to all that the ATM4 adds the ability to render recorded space in such a realistic way – that you might forget the existence of the walls in your listening room.

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The treble performance is one of the reasons, why this amplifier is a great match with the somewhat dfensive treble performance of the Quad ESL 57.
Those stats do not like overly warm amplifiers – to get a realistic top end, you have to match the ESL 57 with an emplifier, which sounds very open and uncompressed in that area.
But if there will be the slightest glare in the high frequency spectrum, you will detect that in less than a second with these legendary speakers.
There are so many transistor amplifiers, which seem to have a tremendous resolution in the treble – but they sound harsh and awkward. The ATM4 ist one of the very rare examples, which can easily compete with the treble performance of the best class A transistor designs at the very low impedance settings the ESL 57 brings along – but shines without any hint of grain or synthetic treble performance.
In other words the Air Tight ATM4 is one of the best amplifiers I have heard till now teamed up with the Quad ESL 57 or the BBC LS3/5a!!!

Classic design:

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The ATM4 is made in a very high quality fashion.
The whole casework is made out of welded steel.
The bottom of the amplifier is constructed with a thick sheet of copper – the whole enclosure is able to shield the electronic parts inside of the amplifier – the copper bottom plate has also the function to isolate the amplifier from vibrations.
The casework is extremely sophisticated – all tubes are located on top of the  main case, the whole electronic is located inside of this case, the power transformer, an EI core type, is shielded and placed beneath the output trannies on the right hand side of the tube compartment.
The whole circuit is made without any use of printed boards!!!
If you open the electronic section of the amlifier you will detect top class components selected with a certain sound in mind. The whole construction is made by hand and the quality and craftsmanship is of the highest standard – those amplifiers are not cheap, but there is a great chance, that you can pass them on to your children – a timeless piece of audio gear!

Some Tips:

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Air Tight amplifiers do not like to be treated in the newest fashion of upgrades achieved with “High End” gadgets and accessories the HiFi industry has on offer.
These amplifiers do not like any isolation base or replacement of their original feet with spikes or other constructions. Put them on a stable wooden piece (solid wood is preferable) of audio furniture as companies like Box Furniture in the US or LignoLab  from Germany offer to you – and they will perform perfectly.
Miura San made the amplifiers and preamplifiers in a very special way, they bring their own damping devices with them – the heavy welded steel chassis and the special applied copper bottom plate is everything these type of gear needs.
The same could be said about the usage of tube accessories like tube dampers –  spend your money elsewhere!!
Any damping gear like HRS isolation devices for example will make the sound slow and overly ripe, the leading edge sounds compressed and the whole sound looses focus and speed.

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The usage of heavily screened power cables, more so with some magical boxes in between the cable structure is a also not recommended with these classic amplifiers. Use unscreened power cables or – my tip – the traditional Belden power cords and you will receive the best performance.
Keep in mind that Miura San designs his gear with pure copper only – so keep it that way – in my experience a mixture with copper and silver as a conductor will result in  a strange behaviour of upper frequencies,  which is seldom predictable. So there might be a great chance, that the newest fashion in silver cable development will end up at selling platforms like ebay.
Keep it simple – use Belden interconnects made with pure copper, or if you want to have something special, which I highly recommend, try to get some Chris Somovigo designed cables made with a copper tube inside. Chris made in the last couple of years a confusing amount of cables branded under different names like “Stereovox”, “Stereolab” or “Black Cat”.
Not all of his designs are worth to be tested – but those with the copper tubes inside are one of the best matches, you will find for your Air Tight gear.
Beside Belden and Somovigo designs, there is also the German company Auditorium 23, which developed a range of interconnects and speaker cables, which will also sound excellent!

To make a long story short – skip power conditioners, exotic power cables, silver wired interconnects or speaker cables, forget about all the expensive and exotic damping devices and platforms – my strongest advice is: Let this type of gear as it is!
It is fully developed and it does not need any help from any HiFi accessory company!
To prove that: In the Air Tight stable there is no latest fashion. It might be no surprise, that some designs Miura developed 30 years ago, are still unchanged in the companies portfolio – something which is quite unique in the audio industry!

All classic Air Tight amplifiers are made with the 600 Ohm standard in mind. So any of these classic power-amplifiers will have an input impedance of 100 Kohm and needed to be paired with a preamplifier with 600 Ohm output impedance or less  – to get the full frequency range this gear is capable off.
For example the very, very good Hovland HP 100 preamplifier with its unusual high output impedance will be not a good match with Air Tight power amplifiers, you will get a rolled off bass performance.
A logic step would be to mate these amplifiers with their stablemates  – the also amazing Air Tight preamplifiers – but that is another story for another day….

Stay tuned

E. Strauss