Medialux

In Part one we discussed in which way the difference between different tubes can be determined.This essay should give some global hints in which different brands of the most important NOS tubes of the ECC83 (12AX7) family differs in sound Gestalt used in a line gain stage only. Please read that again….I am only referring to a line gain stage – no driver, splitter or decoupling stage etc.!!!!The subject of the sound portraitures down below based only on long plate tubes made bevore 1960 – with short plates made in the 60ties (last century) the outcome would be different regarding Amperex and Mullard as also Siemens Halske ECC83 tubes.

The difference between long and short plate versions of those legends are clearly detectable and in some special cases the colour in which the different tubes render the music changed during the changeover in construction dramatically.As a rule of thump – and just that….I would prefer the ultra classic ECC83 (12AX7) from the mid 50ties over there more „modern“ stablemates made from the beginning of the 60ties on.That brings us to the question why the tube industry once stopped making long plate ECC83 versions (letting alone Telefunken – the Tele ECC83 was ALWAYS a long plate ECC83)?The reason is, as you already guess – not the sound quality of those tubes, because we music lovers are not the market segment which was targeted by the tube industry…The main features of electron tubes was dictated by their usage in military environments. With the beginning of the cold war, military development and the speed in which all this took place was unparalleled in the history of mankind. Shortly after the second world war a fighter plane for example was driven by a piston engine and a propeller. The most powerful specimen could squeeze out of their V12 engines a figure around 2000 horsepower – which is really impressive…but already during the last years of the war the Messerschmitt ME 262 pointed towards a new direction – the jet engine!With this upcoming technology a lot more was possible as any designer of a piston engine could ever dreamt of – the angle off attack got smaller and smaller, the speed raised in unknown regions and the outcome was a tremendous increase of G forces a pilot has to withstand as also the tubes which supplied his avionic suite with the necessary electronic parts.As long plate tubes are much more prone to microphony and are not rigid if used with heavy G force loads – the industry had to go back to the drawing board. Born was the short plate construction, and also special military features as triple mica tube versions, double support rods to hold the getter ring – even special constructed or coated glas was developed and a lot of other techniques which made the electron tube robust enough to withstand a tremendous amount of mechanical stress. Imagine those little glowing glas bottles were used in military aircraft till the end of the 70ties – where a fighter plane was able to fly much faster as MACH 2!!!Now you might ask – why the hell the military aircraft industry used tubes throughout the beginning of the 80ties…??The reason was simple and very fiendish….If a nuclear weapon detonates a huge electro magnetic impulse (EMP) takes place – and this is sooo huge that a transistor would melt down in an instant.Later on the industry found ways to overcome that problem – but it took them some time…
A little side story:At in the beginning of the 80ties one Soviet pilot with his Mig 25 decided to emigrate into the west and landed his high tech super jet in Japan, the Japanese and US aircraft technicians were stunned as they opened some of the service flaps at the nose of the MACH 3 capable fighter jet and found…..tubes!Among them was a specific tube totally unknown in the western hemnisphere – a tube which got famous in the High End world, the 6C33C triode which Victor Lam helped to get very famous, as he used them to construct one of the finest SET amps ever made.Isn´t that a wonderful turn…..???
Lets get to more peaceful stuff and dive into the sound characteristic of some of the most famous long plate tubes of all time:

Telefunken ECC83 Long Plates:

The Telefunken ECC83 comes in 3 different types, the Ribbed Plates, Smooth Plates and the very special ECC803S which is a frame grid construction and beneath the Tesla ECC803S, which copied that construction one of a kind.Putting the ECC803S out of the game for a moment to discuss the much more common Smooth and Ribbed Plates:Both tubes differ oh so slightly in their sound characteristic, and that difference can only be detected in very high resolution audio systems – because both share the same basic character – or better the lack of it.Both tubes are acting in a very neutral fashion, the only difference which makes the Smooth Plates for some audiophiles more desirable is the fact that the Ribbed Plates are slightly more analytic than its stablemate.This analytic touch refers to the upper presence section and the top end, were the Ribbes Plates are a little bit more energetic and can produce a slight glare, if the designed circuit is not up to the task.If your preamp or amp (remember – I discuss only the use in a gain stage) is a little bit more on the warm side of neutral it might be exactly the tube which the doctor ordered. So it makes no sense to divide Smooth and Ribbed Plates in different quality categories – they are both outstanding.If we start with the bass response of these classic masterpieces, we might be in for a surprise, because the Telefunken ECC83 creates one of the most realistic bass responses of all ECC83 tubes I ever heard – and I heard and possed a lot of them! A lot of internet rumor is dealing with a sound often described as a little bit thin and skinny….If your Telefunken sounds like that it might be a good chance that you picked a heavily used specimen far away from NOS or near NOS….True would be the fact that this tubes are acting very lively, fast and very articlulate. This is not a slow and heavy bass Gestalt it is full of tone and shares with you any shade of colour in a stunning realistic fashion!The mid spectrum is were the Telefunken is reference class – I know of no other ECC83 (12AX7) were this very important frequency range is rendered in a better, more realistic way – the only competitor comes from Telefunken itself – and it is the ECC803S!The dynamic shades the classic Tele can render is phenomenal and even more stunning is the micro dynamic behaviour of this masterpiece – it can sound so damn realistic that you sometimes think the artist is with you in your listening room!  All these little things – a movement in the orchestra, a little breathing of the solo artists bevor he starts with his performance, a noise from a violin bow hitting the music stand…all this is rendered in a spooky realistic fashion. The Treble is open – yes it is very open, while the Smooth Plates ads a little touch of warmth to the sound were the Ribbed Plates does not –  and are maybe the more neutral tubes?On the other hand this openess and uncoloured, almost neutral sound Gestalt can reveal any mismatch in your system – a wrong adjusted cart, a too lively room acoustics or harsh sounding digital playback will be rendered as it is…so there is no forgiveness in the sound of a Telefunken ECC83. But if your system is very balanced this tube is hard to beat – very hard indeed!The biggest competitor might come from the same company but a different plant – while all Telefunken ECC83 were made in Berlin, the ECC803S was born in the Ulm plant and was also produced there. The serialnumber of any ECC83 begins therefore with a capital letter B for the plant in Berlin, while Ulm produced Telefunkens have the capital letter U at the beginning of their number code!The ECC803S was made for very special applications, be it medicine technology or measurement gear as also the finest tele communications equipment and also audio applications. It is in ALL parameters a step ahead of the standard ECC83!That includes a phenomenal quietness and its unlimited resolution. This tube is a one of a kind super ECC83 and maybe the all time reference if we discuss neutral sounding ECC83 or 12AX7. The biggest problem – this thing is so damn rare and therefore so expensive, that the uninitiated tube lover will get a shock when it comes to the price figures real NOS examples can achieve today…some of us will buy a nice component or even a whole small system for that kind of money.So take this little excursion just as what it is ment to be…this thing was once in existence and has now nearly vanished from any circulation…get over it and lets continue!The soundstage a classic Telefunken ECC83 is able to produce could be one of its most important attributes….because this tube belongs to the rare breed,  which is able to reproduce width and depth with the SAME realism. A lot of tubes are in existence which might be able to render a wider stage – but most of them will not have the same ability to give us the so much desired third dimension – the Telefunken does it all!This tube is one of the best possibilities if you are searching for some ultra competent ECC83 for your phono stage. It is so quiet, lacks any tendency of microphony or hum and can handle clicks and pops with their tremendous dynamic peaks in a way that those signals remain what they are, just short events – there is no compression of those nasty signals which will stretch them at the time domain – the last thing we would want in this particular application. One of the best ultra high end allrounder out there and a tube which can show the quality of a specific smplifier design – be it a power amp, a phono stage or a line stage!

Mullard ECC83 Long Plates,  Goal Post Getter – the legendary MC1:

This particular Mullard was the first European ECC83 in existence – and it was only built for a period of roughly three years – so it is a very, very rare tube with a reputation second to none.There are audiophile tube lovers who are stock piling them, because they do not know how to substitute their unique sound character – and yes – that is an impossible task – nothing sounds exactly like the Mullard MC1.Its successor the F91 comes close to the unique performance of the MC1 and is not so damn scarce but the MC1 does all its special skills a tad better!What makes this tube so famous?If I should sum up what would characterise the special sound gesture of electron tubes – the answer might be – „listen to a Mullard MC1“.And there is a lot of truth in that claim – because this particular Mullard is the epitome of classic tube sound in the ECC83 family. It has a bold and powerful bass with a tremendous amount of texture in it. The bass is of that kind which hits you physically – you will feel the punch instead of just listening….This specific performance character will transform the listener to someone who is not anymore just listening – instead you get physically involved into the music. The midband is lush and extremely colourful and at the same time you get a three dimensional sensation in the lower mids, no other ECC83 can match this. The body of a singer is not anymore a flat section in between your speakers – it starts to be a real three dimensional human being. The presence is a little bit recessed – it is defensive in its ability to render micro dynamic swings – which gives the MC1 Mullard this warm and cosy sound Gestalt. If you are an opera fan – you are in for a treat, because even the most demanding soprano voice will be rendered that you think….lets turn up the volume, were other tube owners will think off doing just the opposite. The treble opens up in a very nice way – a sort of wet delicious treble performance with a lot of sparkle and shimmer. This tube gives you a delicate but also firm treble experience. Sibiliance sound so damn real and beautiful and are never rendered in a  harsh or edgy style. The strings tone, this gems are able to produce is phenomenal – one of the best you will ever hear with ANY ECC83 – and even in big massed string sections the Mullard MC1 is able to separate the things without loosing its tremendous ability to speak with one voice. The treble has even a slight analytic gesture – but so smooth, that this kind of analysis will never be too much. I would call it exactely that amount of precision which makes the sound very believable and real!The stage rendering is big and bolt – it is like watching a cinemascope projection, truly amazing.On this stage the MC1 paints the individual sound sources not as strictly pinpoint events as a Telefunken will do – the Mullard uses a broader brush but has a phenomenal ability to be very detailed at the same time.What the Mullard can not do in such an impressive way –  is to render endless layers of depth. The reason for this lack of three dimensionality is its slightly recessed presence range. The lower mids are rendered in spectacular 3D fashion – but the presence register lacks that ability and sounds more flat.The Mullard is not an up front sounding tube, the stage begins slightly behind the speaker plane and never in front of it.The whole bold sound Gestalt is like a warm cape which embraces you – an amazing experience!The MC1 is not comparable with any later made short plate Mullard – which sometimes can sound a little bit dull, because they lack the stunning resolution in the upper treble the MC1 has in spades.But keep in mind – such a MC1 Mullard is no tube to fit all ECC83 positions in an audio chain – because at the end it would be too much of a good thing – but it is a phenomenal possibility to voice a system.I like to use this tube in line gain stages or the input section of a power amplifier – not so much in a phono stage which is the result of its somewhat slightly coloured sound signature.Such a MC1 can be magical with a modern high resolution cart…because it kills any hint of harshness in an instant – what is left is a high resolution smoothness which is hard to achieve with anything less than this legend!It matches very, very good with a Telefunken ECC83….I would call it a dream team!

Amperex Bugle Boy 12AX7 Long Plates Foil D Getter:

The Amperex is the next legend in this gallery of some of the most famous ECC83 tubes ever made.The Amperex can be also found (the European labeled version) as a Philips Miniwatt – both are exactly the same tubes (for more information, please refer to my Amparex story on this blog).This legend from the Netherlands is as scarce as the Mullard MC1 – because it was made also only for a period of three years. This particular tube is a little bit the opposite in sound aesthetics than the Mullard MC1, because it is slightly recessed in the lower midband (were the Mullard shines) and very, very lively in the presence section (were the Mullard is slightly recessed). The presence rendering will transform the acoustic presentation to a near erotic experience. If you ever listen to a well recorded female vocal, you will think twice about the last sentence, because all the air and presence of the vocal is rendered in such a phenomenal dynamic way, that your brain tells you, the singer is very, very close to you. The reduction of distance makes this tube a very intimate experience, the up front Gestalt delivers a three dimensional sensation which I never heard with any other ECC83!This comes at a price – if you are a classic music fan listening to masses strings, you might notice that the Amperex  emphasizes the bow over the tone. Strings will come closer to you – because presence is always equivalent with being close to the sound source and you will get a more rhythmical presentation as it would be if the Amperex were close to neutral in its performance – which it is not.This tube is something special for vocal fans as also pop and rock lovers – there are maybe better choices if you are a classic music lover!But – do not get me wrong – we are speaking about nuances – if you only roll such a tube in just one spot in your entire system it cpuld be transformed from something very nice to something magical!. So the same I mentioned already in conjunction with the Mullard MC1 is also true in the case of the Amperex – do not overdue it….and enjoy a tastefull tube mixture!!!!If your system is very balanced throughout – this little tweak can make it all….The Amperex Foil D Getter ECC83 can not be substituted by any other tube I know off – which makes this thing as desirable as the Mullard MC1. If your speakers are a little bit recessed in the presence spectrum this tube can also correct such an imbalance in a phenomenal way. The stage of the Amperex is somewhat smaller as with the Mullard MC1, but it is rendered with pinpoint accuracy and let you easily locate each instrument in a very precise fashion. The real sensation is its ability to render the third dimension, the depth of the sound stage – which no other tube can do in a comparable way.As the Mullard also the Amperex is a „tuning“ tube which should not be used in a phono stage. First the special character will form our source signal in such a dramatic way, that we have to fight in all other stages to get back a balanced system performance –  and secondly, maybe more important….as these tubes are so scarce today the chance to get some phono grade ones is close to zero….So use this magical „Holodeck“ tubes like a three star coock is using spices…try to get all the three dimensional sensation without loosing any neutrality. To do so, the Amperex will match up perfectly with a Telefunken ECC83….

Lets have a small break…..I already guess what you think at this point:„Let´s put Mullard MC1 and Amperex Bugle Boy Foil D Getter Long Plates together in our tubes audio system…., to achieve true magic.“I can assure you – I had this idea already – and it does not work!In fact the sound becomes so unbalanced and coloured, that all the magic is gone for ever –  which is a good example of investing in some of the best small signal tubes of all time a huge amount of money while ending up with something which sounds totally inferiour to the stock tubes your device came with!!!!!So be warned – think about the three star cook….

Valvo ECC83 Long Plates 45° O Getter MC2:

This Valvo was made in the plant in Hamburg during 1958-1959 being not a relabeled Philips Miniwatt (from the Netherlands) and is somewhat unknown outside of Europe.Most American tube lovers think it is just something been made from the Herlen Factory in the Netherlands – but it is not.This specific Valvo is a development from the Valvo factory in Hamburg and is one of the highest quality ECC83 which can be found!If we have to characterise its sound, it would fall in between the Telefunken ECC83 Smooth Plates and the Amperex Bugle Boy Foil D Getter – and that is something which could work wonders in your system!The Valvo 45° O Getter Long Plates are capable to be used in a phono stage – be it a high gain type or something under 40db of moving magnet gain!This specific tube is as noise free as the Telefunken and does not compress clicks and pops which do not stretch these nasties at the time domain and sends them close to the border of our awareness.What this particular long plates tube gives us is a stunning neutrality with a hint of that sexy Amperex 3D Gestalt and the ability to shorten the distance between us and the recreated performance of our beloved vinyl records.The Bass is super fast but at the same time bold and powerful. It does not hit us like a Mullard will do, but it has a punchy expression which can hardly be ignored. It lets us feel the music with our heart and soul while also the intellectual oration is clearly there! It combines in an unmatched fashion exactly these two levels of music listening culture.The Midband is phenomenal clean and uncoloured while the upper presence has an up front character. Treble and air are oh so slightly warmer rendered it is the case with a Telefunken ECC83 – but is is a very subtile amount of warmth which does not sacrifice the fantastic resolution these tubes are capable of.Combined with a hard to describe liquidity it is another aspect of what people think a classic tube sound should be.It is a very competent aesthetic which we hardly are able to withdraw.The Valvo is not a kind of „tuning“ tube – it can be used in a wide range of tubed gain stages be it a phono stage, a line preamplifier or the gain section of our power amps.A very, very competent all rounder with an amazing sound Gestalt!And one of the most flexible long plate tubes ever made!Like the Telefunken the Valvo MC2 has this hard to describe, almost scary ability to render microdynamic shades which can make all the difference in realism of a music reproduction system!The stage dimensions are close to what the Telefunken is able to create with just a tad more lively 3D rendering in the presence register as also a little recessed rendering of the lower midrange.This tube sounds warm AND detailed at the same time – which is very seldom seen character and can transfor a whole system in something truly magical – one of the rare breed of true all round super tubes in the ECC83 family!

Siemens Halske Long Plates Double Getter Support MC1 – M5:

The Siemens Halske is a tube which can be used in the gain stages of our phono sections, like the Teleefunken ECC81 and the Valvo MC2. It is as noise free as the Telefunken with the same ability to deal with clicks and pops. But the Siemens is not for everyone….It is nearly the opposite of what unexperienced people think a tube should sound like…which of course is not more than a stupid simplification.The Siemens MC type long plates have a tremendous amount of resolution – in that aspect they are the only substitutes to the Telefunken ECC803S. This resolution comes without any grain or harshness and is super smooth. It is like you drinking a sip of really cold mineral water on a very hot summer day – got the picture???This is not a warm tube, it is tremendously open and agile and full of details and can show layers of colours without any restrictions.The Siemens does not only produce one of the most open and dynamic treble and air renderings of all long plate tubes – it delivers an unbelievable powerful bass at the same time. With the Mullard MC1 together it is the only European tube wich can compete with the Bass Gestalt of some of the best US tubes !This characteristic results in a somewhat defensive mid band spectrum which attaches a slightly HiFiish sound colouration which is typical for the famous Siemens MC types of tubes. This HiFi character is more prominent if you buy later MC Siemens…like the MC3 – 5. The first two versions show this special character in a more subtle way!The Siemens is able to render an amazing stage width as also a phenomenal depth. The ability to show us the back wall of a concert hall is outstanding – you can WALK trough the soundstage and if you close your eyes it is not anymore your listening room you are sitting in – you booked raw 3 and are touched by the music in a very immediate way!If we plug too much of these little wonders in our tube amp chain – the Siemens will transform such a system in something were I would use the term „audio microscope“…. Some of us will like this veuyeuristic style of listening – but to avoid shifting the whole performance to something we can have nuch cheaper with transistor gear, the system must be voiced in a tremendously balanced way.And…a very important hint….if you use real vintage gear – the Siemens Halske MC long plates ECC83 can transform such an old classic system in a way you hardly believe….These are real super tubes in terms of resolution and bass power – and with the Telefunken ECC83 one of the best choices to be used in the gain stage of your phono preamp! The type of resolution can be truly magical – but do not overdue it….music should retain its holistic Gestalt….
RCA 12AX7 Black Plates JRC:

This military version of the RCA 12AX7 is one of the best quality American 12AX7 ever made!The standard version became very famous by guitarists around the world,  because classic Fender amps do only sound as the are supposed to – with this legendary 12AX7. So you will compete with a large number of musicians while hunting for those tubes which are getting more and more scarce today. The JRC version is even rarer but it is worth to look for exactly this specific tube, because its sound is even nicer than the standard RCA.The first thing we will notice if we switch from any European super tube to these American gems is the deepest octave of our music:Only the Mullard MC1 and the Siemens Halske MC1 and MC2 can compete with this type of bass rendering. The bass has a phenomenal dynamic as also a tremendous amount of real punch – but it is not the fastest bass Gestalt we heard till this point. The attack of the tones are slightly rounded while the tone in itself has a very dense character!The mids are a little bit comparable to the Mullard MC1 – warm and very rich in colours and textures – fantastic!What separates the RCA from the Mullard is the higher presence register – were the Mullard is slightly muted, while the RCA shows a tremendous openess killer dynamics! Think about a clean Fender guitar sound – and you get an idea…this crystalline presence with a slight touch of glassy gesture is typical for this legendary tube!It enriches the musical performance of an amplifier in a very special way: As the Amperex Foil D Getter tubes this RCA is able reduce the distance between you and the recorded vocal performance in such a way that we face an intimate performance with a high degree of emotional involvement. The RCA lacks the ability to show layer after layer in the third dimensio in comparison to the masterpiece from the Netherlands. It is able to render a huge stage width but the sound Gestalt is clearly flatter than with the whole illustrious European circle above.At the top of the spectrum the American tube seems to be slightly recessed which might be a result of its highly dynamic presence rendering – a sort of masking effect occurs. The attack speed raises towards higher frequencies. As a result we have a very fast response from around 800 – 1Khz to the upper limit of the spectrum. While the bass response lacks that immediate action the interesting thing is – the tubes does not sound incoherent…far from that.The RCA shows also all the attributes not so much involved audiophiles would suggest a classic tube sound should be. It can be nirvana in any power amplifier gain stage but beware to use this stuff in a phono stage or even a line gain stage – the colouration would be much to heavy!
The RCA has a visceral sound Gestalt – it is like you are able to touch the musicians and it has the ability to let you dive into the music. This tube touches your heart and soul – and is a top recommendation for those people who like to listen mostly to rock music!

This is only a selection of some of the most famous long plate ECC83 tubes – so it is not a complete overview – and it is my humble take on giving you some basic sound descriptions to make tube rolling more predictable.It the next chapter I will discuss the two tube families ECC81 und ECC82 and in which they differ from its stablemates ECC83….so
stay tuned
E. Strauss

We will discuss here the original vintage GEC KT88 not any of the reissues made by the Russian company New Sensor and labeled with the brand name Genalex Gold Lion nor countless Chinese  made copies. The subject of this essay will be the vintage legend made in the period from the end of the 50ties till the end of the 70ties (last century).

The KT88 Situation today:

If we have a look at the countless offerings of KT88 tubes today we have to determine, that none of the actual offerings are real KT88!!!!! – Most of the tubes we are able to buy today are in reality modified 6550 derivates. That is also one of the reasons, why amplifier constructions which are based on the original GEC KT88 will blow such tubes and / or why the operating time of one set of brand new tubes is ridiculously low. If you want to drive your legendary Air Tight ATM2 with modern derivates of the original design, you will face a catastrophic situation: Some sets of brand new tubes survive less than half a year – then one of them dies with heater defects or you face cherry red anode plates wich you have to react to with strictly conservative bias figures to save the tubes and also the amplifier and its output transformers.

With the modern Mc75 or MC275 from Mcintosh you face a different situation – Mcintosh changed the factory installed tubes years ago to 6550 types – and if you plan to use modern KT88 you might be surprised that the sound characteristic does not change accordingly. There are only very small sound differences we are able to detect. If you ever had a chance to compare one of the best vintage 6550 – the Tung Sol black plates to original GEC KT88 the difference will be jaw dropping! The big advantage of the more modern designed Mcintosh amplifiers is the presence of security circuits which shut down the whole amplifier to save the damn expensive thing. To prove the actual situation, you might be aware of a complete design change in the Air Tight ATM2 NEW, which was released at the beginning of 2020 to address the problem of the actual KT88 situation. Air Tight changed the whole circuit to prepare the classic design to be able to function with what is available today…..

The Sound difference:

Lets say you own a Mcintosh MC275 and some nice audiophile fellow would lend you a quad of original GEC KT88 to compare them against the Gold Lion reissues from New Sensor available today, you might be questioning the sanity of your hearing ability…. The first thing you will detect is a complete different treble presentation between both tubes. The Gold Lion reissue will sound closed in and at the same time aggressive and harsh in the treble and upper presence spectrum. The original GEC KT88 produces a sort of airy treble resolution with a silky smooth gesture the reissue cannot match – it is not even close. Some tube retailer companies will tell you that the process of cyrogenic treatment would solve the poor treble reproduction character of the new design – but that is in my opinion barely noticeable.  The New Sensor tubes upper mid spectrum does not feature any agility  – the performance is blunt and graceless. The vintage originals are very, very agile and give you so much more texture and a 3D sensation, that you won’t believe the performance difference. These attributes ensure that the reproduction of a grand piano or a violin with all their complex harmonic structures will remain. In the broad midtone section of the spectrum the original GEC KT88 sounds completely unforced and liquid with such an enormous amount of naturalness the reissue cannot match – the difference is not subtile it is dramatic. The bass register of the old originals are full of authority and speed – in comparison the modern construction sounds slow and sluggish with a sort of roll off near 30hz. With all that said the most dramatic shortcomings of the reissue Genalex is the spatial experience. The sound does not detach from the loudspeaker membranes – it does not flood the room, it does not put the listener in front of a virtual stage….The difference is like comparing 70mm cinemascope film material to a VHS video cassette.

The original GEC KT88 shares nearly the same nimbus as the legendary Western Electric 300b – till today no new tube construction can replace the original design.

Availability of the famous GEC KT88 – how to detect the legend:

In todays used market the different types / labeled GEC tubes have almost vanished from circulation. Accordingly the used price raised in the last 10 years to a degree were people outside the hard core tube scene will think we all have lost grip!!!! But the biggest problem is to find a good quad of those tubes. Under these circumstances it might be interesting how to determine the quality of a used offer on ebay. Heavily used GEC KT88 tubes are easily identifiable by small brown getter flashes, where there once was a shiny silver getter flash. Keep in mind, the most common original KT88 had 3 getters – two at the side and one on top. Later – at the end of the production there was also a 4 getter version with a 2 top getter construction, which used a completely different plate coating. Instead of the matte greyish black ugly plates of the classic original tube, these versions (also available with 3 getters) share a bluish metallic grey coating on their plates. It is not clear until today if these last generation of classic KT88 were made in Great Britain – or if the MOV (Marconi Osram Valve Company), the maker of the legend, outsourced the production to China. All these last generation shiny plate KT88 are labeled “Gold Lion” and share a small print of a stylised lion on their glass surface which is executed in a yellow goldish colour. So the first thing you have to watch out for is the coating of the plates – because the less sought after shiny plate KT88 are today as expensive as the much better original ones. If we analyse this last version of the vintage KT88 tube strictly, we can speak of the first reissue in existence. The boxes of those tubes are mostly orange and black coloured with the Gold Lion imprint and most of the tubes from this batch normally share black tube bases (under the aluminium collar) instead of the brownish colour of the true classic.

Much higher in demand and also better sounding are the older tubes which we can distinguish from the last generation by looking at the plate coatings. There are more differences – but the coating is easy to detect and therefor a good reference point. The lables which you will find on the old originals may differ – the MOV company made their famous KT88 also for other companies as for example Mullard which are rarely seen today. Mullard itself never made a KT66 or KT88 on their own! With the MOV companies different tube labeling, we face a very complicated branding system, which might be confusing.

Nearly all exported tubes share a label design which is mostly executed with the beautiful Genalex Gold Lion design. These tubes served as a model for the New Senor reissues. Those tubes came in fancy boxes coloured in red and printed in gold with the name “Gold Lion”. Inside you will find, if you are lucky and have an unopened original in front of you, a sort of plastic bag in which the tube was shrink wrapped together with a shock absorber construction directly derived from the NASA Apollo Programm;-))) The imprints on the glass show a big gold lettering and the famous stylised lion, furthermore the aluminium collar wrapped around the tube base is designed with red Genalex stickers. Another typical US brand of the British original was Gold Monarch – the boxes are as fancy as the Gold Lion ones – the lettering is nearly equal und the tubes are also very, very beautiful. The European customers did not get that fancy outfit (keep in mind – it was always the exact same tube!!!!!) – European GEC KT88 share normally the turquoise coloured GEC label which changed over the long period of the production. Later types have a modification in the label design and colour – now it is printed in a pastel yellowish colour – but also marked with the GEC lettering. There are also versions built for military applications which normally have no white KT88 lettering on the glass surface, instead these specimen used the military designation CV5220. All genuine MOV tubes share an additional white coloured rectangular stamp on the glass body which shows the date code and the letter Z, which is the indication of the Hammersmith factory in England, where all the legendary tubes were made. Your goal is to pic a quad with nearly matching date codes and good readings for transconductance and mutual conductance with good getter flash and no or only slightly brown discolouration. And yes – it is like winning the lottery. A brand new quad of these scarce tubes in original boxes is like meeting your dream woman – and it is nearly as expensive…;-)))

The different versions:

The race between the big tube suppliers to reach more efficiency and output power, pushed the companies to increasingly complex constructions. In the USA the 6L6 GC got it’s big brother with the 6550 and the British tube industry must answer to that offer from Tung Sol and their famous black plates 6550. The MOV company designed the kinkless tetrode (thats why the tube type is named KT XX) – the much stronger stablemate of their KT66 design,  which was used in the Quad II amplifiers to very good effect (to name just one example). MOV also designed a substitute for the widely used EL 34 penthode from Philips / Mullard which was protected by patent. They modified their kinkless tetrode deign to built their legendary KT 77 design, which is a drop in replacement for any EL 34 tube – today more rare than everything else from the MOV company! With the KT88 the British manufacturer decided to design a tube specially made for audio applications – in this regard this tube was a big exception, because most tube designs were driven by the defence industry. When Mcintosh designed the MC275 and also the MC75 monoblocks they decided after some intense testing to use the new KT88 instead of the American made Tung Sol 6550, which was a kind of scandal in those years. The typical vintage Mcintosh MC 275 tube setup featured Telefunken ECC83, ECC82 and ECC81, a RCA 12BH7 as a driver stage (which was skipped with all modern MC275 / 75 designs) and four Genalex Gold Lion Tubes….this tube setup would cost in todays market nearly the same as a vintage, unrestored MAC would diminish your wallet.

The first version of the MOV companies KT88 design shared nearly the same form factor as the American Tung Sol 6550 – both used a sort of Coke bottle shaped glass body. This version had only one top getter and disappeared completely from the market. The second version already showed the typical KT88 glass body design – and also had only one top getter. These tubes are very, very rare today but sometimes you may find them on ebay USA. There are some audiophiles who claim – this is the holy shit….I mean – this is the best of all KT88 tube types – lacking the experience, I can not confirm that. The next version (3) featured a three getter construction – one on top and two at the sides – this is the most “common” type. If we want to be precise – we can divide this type three in two sub types – but that is maybe too complicated for the first basic explanations regarding this tube type. Type four is the shiny plate model with a three getter construction, I already mentioned above – and type five shares the same construction with the same new plate coating but features a four getter sections.

Is it worth it???

Let me put it this way – if I had no original black plates GEC KT88 – I would sell the amplifier in favour of a nice Lavardin transistor amp or a tube design which uses different types of power tubes which are not as rare (NOS – new old stock) as those legendary MOV tubes. A good substitute would be a 6L6 GC design, because today it is still possible to get a good quad of General Electric grey plates or RCA black plates – which are also far, far ahead of ANY new design (please refer to my essay about the 6L6 GC tube on this blog). The difference in sound culture is so immense, that you cannot ignore this unbelievable quality from the past. None of the actual offerings comes close – even very very expensive modern tubes like the EAT KT88 cannot match the sound of the original MOV design from the sixties. If you now need some sedatives, because you searched for GEC KT88 on ebay and saw the price tags – I am with you….BUT…keep in mind – a new quad of New Sensors Gold Lion will not even come close to the sound of the vintage original – and it will need replacement after 2 years if it survived the first two or three weeks after the initial installation. The vintage GEC KT88 will serve you with its unmatched delicate and complex sound for more than 8 years….which relativises the steep price tag in our days. But do not buy vintage scrap – one of the most important aspects is to use good and nearly new or really new tubes – it is not worth it to buy a tube which is at the end of its lifespan for some bucks less . Tubes – also vintage quality ones –  are an aging species – and old heavy used power tubes cannot deliver what they once used to be.

My little story:

5 years ago I visited Japan with my wife. During this trip we spent a couple of days in Tokyo – and you already know what will follow….I begged my wife to spend half a day in Akihabara (electric city) a district of Tokyo where all the vintage tube stores and HiFi dealers are located. After some hours of investigating where I could hunt some nice vintage tubes we came to a strange sort of electro – market, where zillions of little market stalls with loads of electronic components were located. After tons of wire, resistors, capacitors and transistors my eyes spotted at the end of one of the lanes an old man surrounded with vintage tube boxes…. You might guess wat followed:

Me: “Do you have GEC KT88?”

Dealer: “Yes of course”….

Me –  breathing harder – “I mean real GEC KT88….”

Dealer: “Yes – the old British quality stuff….”

Me breathing even harder – “Can I see them?” – expecting a pair or maybe some non matched singles….

The man behind the small counter grabbed into one of the drawers and guess what…he placed 3 matched quads of brand new GEC KT88 on the table – all with measurement protocols included…..each for a reasonable price. I bought a very nice quad and stored it securely in my camera bag. My biggest concern was the airport security – imagine 4 strange looking glass tubes with a lot of wire and even more strangely looking metal parts – and all that after 9/11 – but the Japanese airport people x rayed my bag and did not ask a single question….

Maybe it is a sort of fashion in Japan to carry vintage electron tubes in camera bags – maybe we strange audiophiles are well known clients for those security guys at Tokyo airport – who knows…..

Happy hunting

E. Strauss

Jack of all trades:

Imagine a cartridge, which can transform some of the most demanding Rock titles to an experience close to the live adventure while sailing smoothly through the grooves with such a stunning silent ride, that you doubt an electro mechanical transformation occurs. And if that is not enough – minutes later the same cartridge can deliver an astonishing realism while playing some classical music. The EMT JSD5 is one of the very rare breeds of transducers which do not have their favourite music. If you ask me which cartridge I would pick if I could only have one – it might be a good chance the EMT would lead my list….

Some history:

EMT was one of the leading suppliers for the broadcast industry. The legendary indler wheel truntables EMT 927 and 930 come to mind, as also the famous 997 tonearm or some of the best CD players money can buy. The company was founded in 1940 by Wilhelm Franz as Elektro Messtechnik Wilhelm Franz Kg residing in Mahlberg near Lahr in the German Black Forrest region. Since 2016 the company is now part of EMT International GmbH, which is located in Switzerland.The EMT JSD5´s origin dates back to the famous EMT TSD 15 cart, which was one of the most used pick up systems within the broadcast scene during many decades.

The construction:

The EMT carts are not the typical low output high end transducers we will find today – instead of producing output voltage figures around 0,2 – 0,4mV – they deliver a very strong 1mV while having a coil resistance of 22 Ohm. This 1mV figure is on the one hand a blessing for those of us, who use a phono stage with a very low gain structure (30db for example) – but on the other hand, almost none of us audiophiles have a step up transformer at hand which can deal with the technical data of such a cartridge. Historically the EMT turntables with their built in tubed phono stages used transformers with a turn ratio of 1:7 made by Neumann (BV – 41) or Hauffe. Those capsules are very, very rare in todays used market and not available any more. EMT´s own stand alone Step Up device, the legendary STX – 20 has also vanished from the used market – and if you are lucky to find such a gem on ebay – be prepared for a very steep price tag. As only insiders might know – there is a cheaper solution from Thorens. They used long time ago some parts from EMT for example the 929 tonearm – or the TSD 15 cart….these Thorens step up devices share the same capsules as the STX -20 from EMT itself – but are housed in a cheap plastic compartment and are not near the quality standard of the beautiful crafted originals – but if we spend a weekend with some do it yourself work – we can transfer the capsules into a nice enclosure with some good cabeling and professional RCA sockets….

One other very, very good option would be a Cotter PP step up transformer….These extremely good transformers are configurable to fit the EMT carts – the only thing you need is a solder iron and not more than 20minutes of your time. The configuration schematic  of  the Cotter PP can be downloaded from the web and is completely straight forward. Last but not least EMT International, which  is aware of the precarious situation, brought the new STX 5/10 to us – designed by Micha Huber, the father of the well known Thales tonearms, who is actually also the man behind EMT International. The only disadvantage of the wonderful STX 5/10 is a very, very steep price tag of over € 7000,-!

If you have an active phono stage which features adjustable gain, as well as variable loading – you are ready to play….with no further investment. The EMT works best with loading figures beyond 200 Ohm and needs around 50db of noise free gain, which is not be a big deal for most of the modern transistor phono stages. Nevertheless – the more classical and historically correct way to play music with an EMT cart,  would be a tubed phono stage mated with a 1:7 or 1:10 SUT – depending on the gain structure of the preamp. Regardless of using an active transistor or a tubed phono stage teamed up with a suitable step up transformer – please keep in mind, that the EMT features a tremendous amount of output voltage. Listen carefully while you are preparing your setup. If your phono stage will compress during the most dynamic passages of your hottest vinyl cuts, you might want to change the gain setting of your transistor phono pre – or change a 1:10 SUT to the originally recommended 1:7  turn ratio type…..With a tubed phono stages a gain structure around 30 – 40db MM gain is a good starting point for an uncompressed sound performance.

The JSD5 features a boron cantilever with a Fritz Gyger cut, one of the most elaborated diamond cuts in todays market. This needle construction together with the EMT damping system is one of the reasons, why this cart can track a record with nearly no limits while being extremely silent in the groove. EMT changed the compliance of the cartridge during the last years – the original EMT carts were all designed to feature around 15cu – the more recent Swiss made transducers now share a compliance between 10 – 12cu and will be a better match with  heavier tonearms. With my example of the JSD5 I hit the sweet spot around 18gr effective mass using my Frank Schröder CB tonearm, which is – as you might already guess an amazing solution for this cartridge.

The EMT JSD5 more so than his stablemate JSD6 which is made by using a Fineline stylus cut – is very sensitive to the correct VTA adjustment. If the cart is set “tail up” the musical reproduction becomes strident and not fluid anymore. Too much of a “tail down” adjustment and all the fine details are gone and the amazing dynamic performance which the EMT JSD5 is capable of is restricted. My advice would be a parallel arm position as a starting point – and 2.4gr of downforce as also a minimum of scating compensation. Adjustments of antiscating might be a little different than you are used to – because there is a good chance that the cart sails through all torture bands of you test record without starting to generate distortion – and even if it does distort slightly at the last test band – it is completely wrong to adjust the scating compensation accordingly – you will end up with a dramatic overcompensation, which will deflect the needle and ruin the perfect phase response of the transducer and its dynamic abilities. Set the cart between the outlet groove of your record and start with such an amount of compensation, that the cart will not move in any direction –  till it catches the groove. This might be an undercompensation – but it is a very good starting point – from there you have to listen to the most demanding passages of your record collection and adjust accordingly – while doing that – listen carefully!

The body construction of the cart is milled of a special aluminium alloy, which is treated with a sort of sandblasting technique to harden the surfaces even more. The design is laid out as a half naked enclosure to avoid reflections or standing waves inside the body shell. It is made in such a way, that the user never gets sweaty while handling the cart and mating it with the tonearms headshell – there is always a large degree of security. The front of the cartridge housing feature a sort of triangular shaped “nose”….which gives the design its unique silhouette. But this “nose” is not meant to be just a design gimmick – if you try to place a Koetsu exactly at the beginning of a record track, you know what I mean….with this triangular shaped “nose” tracking a certain song on your vinyl is a breeze. The cartridge pins are color coded and of high quality,  while the body shell is fitted with drilled mounting holes, which makes the installation very straight forward.

One very interesting detail of the cartridge design is the technology EMT used to place and fix the cart to its housing. The cartridge “motor” is fixed with three threaded cones which allows the manufacturer to adjust the “motor” in alignment to the enclosure. The needle azimuth is also adjustable, because the whole construction is located in a tube, which is housed in a radial frame and fixed with one setscrew. The whole construction enables the manufacturer to adjust the cart with aid of a jig and a microscope to a degree of perfection rarely seen today.

The cart comes in a wooden box of the highest quality and is packed with some goodies also rarely seen today. You will get 3 pairs of precision engineered hex screws of different sizes to mount the cart – together with the suitable hex screwdriver. Additionally EMT encloses a measurement protocol from your specific cart with your specific serial number to the package – a rarity in todays high end scene!!!!!!

The Sound:

The first thing we might detect, while listening to the EMT JSD5 is a tremendous ability to render dynamic swings. This cart reminds me of a DECCA cartridge in its merciless way of kicking your butt;-))) While doing so, there ist a sort of presence that makes you smile. This thing can sound very, very big! The bass performance is one of the best you ever will hear – it sounds a tiny bit over ripe in the 100 – 200hz region – but instead of masking the really deep base – it does the opposite. The bass gesture is astonishing – fast, full of tone and not boomy or fat – it is a spectacular experience but without that typical artificial punch we might find for example in carts like the My Sonic Lab designs. It is more a stringy bass gesture with a lot pf energy and an amazingly fast attack response. There is nearly no colouration in the midtone spectrum – it is rendered as natural as breathing, which is one of the reasons, why you can listen for hours to your favourite music without any fatigue. Treble and air is so well integrated – this is not a warm cart – nor is it analytical or shiny. It is exactly that amount of treble which blends seamlessly into the whole frequency spectrum of this outstanding design. There is always enough analysis while being able to let the music breathe in a wholistic gestalt – amazing! In nearly every parameter this cart is designed to be “on the edge” not a tiny bit to the left nor to the right – it sounds in its own right completely natural!

The spatial information the EMT is able to render is as astonishing as the rest of its outstanding performance. While drawing the sound picture stringent from the mono center onward – it is able to draw a wide stage with also a realistic depth in such a relaxed way, that you never start questioning the realism of the performance. While the center stage is always a tiny bit up front, which reduces the distance to the vocalist and gives you this sexy attitude – the JSD5 is always able to let you forget that you are just listening to a vinyl record – well done EMT!!!!

In todays high end market we witness a growing number of super carts in the €10 000,- range. If you compare one of these extraordinary constructions like the Air Tight PC1 Coda or the Lyra Etna SL with the last generation of the EMT JSD series – you begin to ask yourself – is it worth it….??? Yes – a Lyra Etna SL is able to draw a higher amount of detail – and its ability to start and stop in an instant is maybe unmatched (even more so with the Atlas SL) – the PC1 Coda can distill more micro dynamic information from the record grooves and is an easy match for any phono stage be it a tubed design or a transistorised construction – but the EMT is so well balanced and delivers so much listening pleasure, that you never miss anything. And I mean ANYTHING!

A true classic – and in todays market one of the best buys.

Stay tuned

E. Strauss

If we discuss the reproduction quality of a given High End system there are basically two philosophies present: One group argues such a reproduction system hast to be true to the source. Furthermore there is always a big claim that the result has to sound real – sometimes those people talk about “live sound”…. The other group is not so much interested in technical data, neutrality and equipment wich is “true to the source” – they want something which make them believe that what they hear trough their HiFi setup brings the music to live. It does not matter if the gear overstates some aspects to achieve this “believable” sound reproduction. Who is right????

Is there something like the real thing banned on any sound storage medium?? 

Lets analyse a very simple situation which takes place nearly every day in a recording studio….the recording of an acoustic guitar and a voice. If you think about the guitar and its pattern to send sound waves into the room, you will be aware of a tremendous complexity in which that happens. On the other hand we engineers stand there in a desolate fashion with our microphones and it is absolutely not possible to record the guitar as we can hear the instrument performing in our recording room. We have to choose a directional microphone characteristic because the guitar player wants to play guitar and while he is doing that he also sings the song – one take with two signal sources – sounds easy but it is not. If we would choose an omnidirectional microphone, we have not enough separation between the voice of the musician and the guitar – later in the mix there would be rather no possibility to level guitar versus vocals. We call this  crosstalk. So we have to chose a directional microphone to minimise crosstalk. Normally we would opt for a cardioid characteristic. With this choice we have not anymore the chance to capture the guitar in its holistic gestalt – we start to interprete the sound. Think about using a wide angle lens to portray a given scene versus using a telephoto lens….with the tele lens the photographer interpretes the situation – with the use of a the wide angle lens we, as an observer have to separate the important information in the picture from the surrounding atmospheric details. And be aware….. it gets much worse….because with a cardioid characteristic we face a phenomena called proximity effect….as close we would position the microphone towards the sound source as much the low frequencies will be featured. It happens in a way were it is everything else than an easy task to get rid of that bass emphasis later on with our  parametric equaliser during the mixing process. If we place the microphone within a greater distance we will get too much crosstalk again…

Why is crosstalk something we do not want?

Lets assume that we found the optimal mic position for the guitar at the spot right behind the guitar bridge with a sharp angle in which the microphone is placed….the guitar will sound good…. Now we record at the same time the voice of the guitar player – and therefor we use a large membrane cardioid microphone – lets say a Neumann U87. We “fly” the microphone so that the capsule will point at the section around the nose of our singer….the vocal sounds now also pretty good…

BUT….if we listen carefully to both tracks of the recording we will detect crosstalk from the voice on the guitar track and vice versa. This crosstalk signals have a different phase characteristic because of the running time of sound waves and much worse – because of the different angles we put our microphones towards the sound sources….. If we listen to the vocal track solo it sounds very, very good – now we fade up the guitar track and the vocal starts to gain some strange colouration – some frequencies are extinguished by the additional vocal crosstalk on the guitar track. And the same is also true with the guitar itself – the crosstalk from the vocal microphone damage the pure guitar signal also with a good portion of phase anomalies.

It seems to be such a simple task – a voice and a guitar both performed by the same musician at the same time but we face a tremendous amount of technical problems to achieve a clean and natural sound, and we are far away from the real sound event which we are able to hear in the recording room.

What to do??

A good recording engineer will find a compromise between the perfect guitar sound and the vocal sound – and he always will assess the vocal sound over the guitar sound aesthetic – because everyone can detect any little amount of colouration in the human voice were nobody is able to tell later on how the real guitar sounded.

The guitar itself has basically 3 spots were we can get some characteristic sound aesthetics from. There is the position behind or at the bridge of the instrument, a position were we get al lot of percussive and rich tonal colours from the wooden guitar top. Than we have the sound hole in the middle of the guitars wooden top – there we can get a lot of deep frequencies which reacts much slower that the percussive performance near the bridge – and last but not least there is the neck of the instrument were the left hand is playing the different notes or chords – at this position there is a the largest amount of overtones and harmonics. If you opt for three microphones, than you are in for a real fight against phase anomalies later on in the mix…so you have to listen carefully to the specific instrument and you have to decide at which position  you will get the most of the holistic sound you can hear at some distance in the recording room.

Now lets change the situation – you are not anymore recording a guitar with a vocal performance in one single take – you have now a whole band or an orchestra…..And what I explained till this point is just a basic entry in the much more complicated  field of recording technology and procedere.

The real thing

As you might realise now – the real thing is already messed up in that moment were the recording took place – and it is not the incompetence of the recording engineer it is the nature of the whole game. Sometimes there is also a complete different situation coming up – the musician has a spontaneous idea – he grabs the guitar and shouts at me – Ekki – start the tape….in such a situation you have no second chance nor time to adjust anything to get the best sound….you just press the damn red button….and – as a matter of fact – this piece of music will make it on the final record you later can buy in the shops…because in was a good atmosphere in the studio and the artist had an amazing  creative moment….you get the picture.

Later in the mixing process we have to correct things like the proximity effect, we have to shape the sound to match  the aesthetic approach of the artist or his producer. And sometimes it is not the technical best piece of music wich is released – because the technical aspect of the music is not as important as the artistic content – yes, dear High End fan….the musical intensity is always more important than a perfect sound – and not infrequently an overly “anal” engineer will kill all the creative atmosphere in the studio – that is, why so many well recorded High End music is boring in terms of  vividness and musical gestalt….( I cannot stand one single track of artists like Rebecca Pidgeon or Diana Krall to name just a few….)

The truth

As you might see the truth is something rarely existing in music recording…and often the truth is not representable….imagine Michael Jacksons song “Bad” – does the bass sound, which introduces the title have a sort of original??? It is generated by a synthesizer and went through many manipulation stages to sound like it does…This sound does not have an original source – and the bass harmonies of Kraftwerks “Aerodynamic” does not either – are they less important than the string sound of Beethovens Eroica???

NO Hifi, High End or whatever stereo reproduction system – no matter how big, how expensive – made by Western Electric or Wilson Audio is able to reproduce the damn real thing – because we already loose the game in the recording process just to mention the least! It is a sort of unfulfilled dream of the High End scene to reach something like the live event – they spent tons of money, suffer from GAS and “Uprgaditis” to come closer to the real thing – and guess what – the majority of the serious High End freaks had their last life experience 5 years ago… If the real thing can not reproduced – what do we talk about in all the test magazines and online articles???? – Please spent a serious amount of money to get you and your beloved ones into a concert hall, if you will spent just a fraction of the money you already invested in your stereo – you can do that on a monthly base – and guess what – it will make you happy – it will reduce the damn High End System to what it is – just a reproduction system….!!!!

Can you believe it???

If you sit in front of a full Shindo system you will have a very special experience – this stuff is not true to the source – it is not linear – nor is it the best in technical aspects like sheer power or THD to name just a few parameters….BUT – you will get something your brain is able to process to something you can believe – something which sounds damn real to you. Another piece of audio jewellery from CH precision or Wilson Audio may not able to feed your brain with enough of that stuff which makes you feel, that the listening experience has something to do with the real thing….Technical parameters means nearly nothing – or to be more precise – at a certain level of technical perfection we are not able to justify a given piece of gear just with their technical abilities….! Imagine you sit at your couch to relax and dive into some great music – lets say it is 5pm – the street in front of your house is occupied by the guys from the garbage collection, in the neighbourhood a child is crying and you hear the TV set fron the deaf guy in the floor above your flat…your turntable is spinning Radiohead “In Rainbows” and you try to dive into Thom Yorkes world of sounds and lyrics. I will guess that a system which overdoes the things a little bit in a magical way – might be helpful – it is like a good pantomime – it has to characterise the special mood in a bold way to make your brain and your heart follow the gestalt of the music instead of listeing to the TV set a floor above. This is an art in which Ken Shindo was a magician – and Dan d´ Agostino of Krell was not….

At the end….

…it does not matter how big your speakers are – how expensive the amplifiers or how perfect the source components – at the end the whole business comes down to arrange a well balanced system, which can deliver the stuff your brain needs to accept the reproduction as something authentic – something real. If your stereo can do that – do not touch it anymore – stay away from audio fairs and High End shops – buy more music – discover new things – try to be open to new insights – and you will be richly rewarded.

Stay tuned

E. Strauss

Air Tight is known by most of us audio aficionados  for their outstanding moving coil cartridges, beside that, some of us associate the Japanese company with classic well made and beautiful crafted tube amplifiers. The Air Tight cartridge portfolio got so much praise and awards in the last 15 years s, that this product category almost outstripped the core business of the company. Air Tight is very conservative in bringing new products to the market – product terms of more than 20 years are common and not something special. As Miura San, the founder of A&M ltd.  / Air Tight celebrated the 30th birthday of the company, it was time to bring out something special to amaze us audiophiles – a new reference cartridge. As it was done in the past, he mated up with Matsudaira San (My Sonic Lab) – to create maybe the best moving coil cartridge known today, the Opus One.

The situation

If we have to describe the character of some of the best regarded carts today, we will come up with attributes like speed and pin point accuracy if we talk about the amazing Lyra cartridges. If we think of a Van den Hul, amazing resolution comes to mind – not seldom mated with a lack of musicality. Thinking about the the Ortofon SPU or the EMT JSD range of carts, we face the opposite character of a Van den Hul – stunning musicality and a rich sound mated with a very satisfying reproduction of our beloved music. Koetsu will give us some of the sweetest midrange in the whole market with a very special realism, which gives us a drug like sound and the amazing DECCA London Reference, is famous for its tremendous ability to render the biggest dynamic swings. – The big question is – can we have it all in one single package without any compromise??

The price

The answer is – yes we can – and it might be the Air Tight Opus One which stand out in combining all the greatness in the different disciplines in a unique fashion. In my book it is the most complete cart ever created till today. This is a bolt statement, I know – but that is what my ears tell me, if I listened to its stunning performance – and as always in todays high end business it comes also with a bolt price tag. In Germany we have to pay around €15 000,- to own such a jewel. Please think about that – €15 000,- that is a sum, were you are able to buy a nice used BMW or a whole stereo system with some amazing LS3/5a speakers mated with a classic tube amp like the Quad KT66 monoblocks and a very, very musical Garrard 301….I cannot help myself – but I am not ready to spent such a huge amount of money for just one single cartridge – even if it is maybe the best in the world. That being said – Air Tight brought in 2018 the PC1 Coda to the market – which is less than half the price of the Opus One, still a very steep price tag but maybe a little less crazy than buying the top of the line cartridge….  Miura San gave us for half of the price of his reference cart Opus One a slightly stripped down version of this gem with is also the successor of the world famous PC1.

Stablemates

Opus One and Coda share a compareable  body construction made out of a special 7075 aluminium material. The body structure itself is made out of two rectangular blocks of this dense and light material, which are pressed together using an interleaved pattern. The characteristic of A7075 is very special and addresses the energy transfer as also the amount of absorption in the cartridge housing itself. A7075 is very dense and can transfer energy in the most direct and fast fashion – but at the same time it has a very unique property of absorbing mechanical energy. The PC1 Coda was developed by using the SME V tonearm – a piece of gear which has not a great ability to absorb any initiated mechanical energy because of its overly stiff magnesium arm-tube. This material selection takes care of a wide margin of different tonearms – which makes the Coda a highly versatile cart.

Technical stuff

The cartridge features a stiffer suspension as we will face it with a Lyra Atlas for example, so it needs to be paired with a tone arm which features an effective mass of around 15g – 18g to get a perfect resonance frequency pattern of 9hz. The cartridge helps lighter armwands with its own weight of nearly 13g.

The biggest technological speciality of the PC1 Coda will be found in its electrical parameters. The cartridge has a DC resistance of 1,7Ohm – which normally results in a very, very low electrical output. But not in this case!!!! – To get a feeling for what Matsudaira and Miura San did here, lets compare the Lyra Etna SL´s electrical figures with the Air Tight PC1 Coda:

DC Resistance          Output

Lyra Etna:                    1,52 Ohm                 0,25mV

Air Tight PC1 Coda     1,70 Ohm                0,50mV

As we can see, the Air Tight PC1 Coda doubles the output figure of the Lyra Etna SL while having almost an identical DC resistance. That being said, Air Tight was able to combine two parameters which are normally opposed – a single layer coil structure with its low moving mass AND a healthy output voltage.

Efficiency – a unique construction

Matsudaira San is the mastermind behind this astonishing, patented technology. But how is all this working??

On different webpages we will find the information that a special coil structur is responsible for the high efficiency of this design – but that is mostly wrong translation from Japanese language into english. The unique principle behind the cartridge “motor” can be found in using a special designed core material, which features high amorphous MU metal! With this material and some very strong neodym magnets together with a high purity copper coil, Matsudaira San was able to create the most efficient cart till today.

That is good news for us record lovers – because a single layer coil structure has a very low mass figure, which enables the cartridge to track the grooves with less inertia resulting in a very accurate transient and dynamic response while giving our (tubed) phonostage an easy task.

The phono stage – and the SUT

If you mate the PC1 with a full active phono stage, I will recommend with a termination figure of around 100 ohm – if you detect oh so small hint of dynamic compression, raise the figure to 200 Ohm. As every phono stage reacts different to the HF peak every moving coil cart is sending into it – consider my advices as a starting point. It all depends on the capacitance of the used phono cable and the internal construction of the RIAA stage.

If you are using a step up transformer, things are slightly different….. The Air Tight ATH2A (reference) SUT was designed with the reference cartridges PC1, PC1 Supreme, PC1 Coda and Opus One in mind. The SUT offers a 1:30 turn ratio in its 2 Ohm setting (as also 1:15 switchable) – and gives us 29db of passive gain! It might be a special Japanese philosophy, which also can be found with other manufactures from the land of the rising sun, such as Kondo – that the gain figures of the tubes phono stages are not impressively high. To compensate that, Kondo and also Air Tight mate their moving coil carts with high turn ratios. Please have a look at the Kondo webpage, and you will find step up transformers which offer 1:42 turn ratios with 32db of gain – and offered to be used with carts of 1 – 10 ohm DC resistance. In the case of the PC1 Coda (and also the Opus One) we will gain a almost noise free phono sound with a small amount of active tube gain – because the cartridge sports a tremendous efficiency and is mated with a SUT which has a relatively high turn ratio for that kind of output voltage. IN pother words the whole phono setup acts like a complex gain chain….To gain an amazing signal to noise ratio from the classic Air Tight SRPP phono circuit, Miura San created with Matsudairas help a very, very efficient moving coil cartridge, which a very low DC resistance that can be mated with a high turn ratio.

If you co not own such a “low gain” phono stage – please be sure, that you choose a lower turn ratio – like 1:20 or 1:15 otherwise both components, SUT and cart might overdrive your phono input. A side note for all Air Tight users who already have an amplifier setup with a phono stage from the same brand – the whole setup will be only completed, if you mate it with such a cartridge. The synergistic effect of the whole phono chain from Air Tight is truly amazing, which does not imply that these outstanding carts do not perform dreamlike also in other environments.

More technical stuff

Other ingredients if the Coda are a boron needle with a semi line contact stylus, which tracks even the most demanding passages of your vinyl collection with an astonishing quiet performance. So this little jewel is not only for your 10 high end reissues – it can also be used with less than perfect vinyl! – Well done Air Tight!!!! The contact surface – as also the whole upper block of the housing is hard chrome plated to generate the most intimate contact between the headshell and the cartridge as also to feature the hardest surface possible to give the mechanical energy the fastest route away from the needle tracking the groove. Of course we get al the bells an whistles which can be found on any high end cart today, as rhodium plates contact pins, which are colour coded, as also a very, very luxurious packing, which is in itself a pice of art!

The Sound

But how does a €8000,- cart of this calibre sound??? In one word – it is the a truly once in a lifetime experience!!!! – If I had to use just one depiction – it would be the word DYNAMIC…. This thing is better than any DECCA cart – it is the most dynamic sound I ever got from my vinyl rig. The Quad ESL57 electrostats did not know what they are able to bring to the table in this regard. I was completely floored from the ability to follow even the biggest or smallest dynamic swings – this is world class performance – and maybe the best you will achieve beyond the Opus One! But it is not as easy as this – because the Coda delivers so much more that the incredible ability to create a frightening dynamic. It has a fantastic resolution without any harshness – I would call it natural – the sound is created in such an easy and unforced way that it seems to be as natural as breathing. The Coda features a holistic sound – it does not that sort of separation we can detect with a lot of high end carts today. The ability to let the music speak with one voice reminds me of the classic studio carts like the Ortofon SPU or the EMT JSD. The PC1 Coda is able to give you all the different shades, all the colours and a fantastic pinpoint accuracy without dissect the music. The amazing quiet ride of the cartridges enables the tiniest microdynamic shades to come to life, which makes this thing oh so real! The ability to render the recorded space is perfect – you get a deep and wide sound with sharp boundaries and a cinematic view to the stage, which is very, very seldom found in such a balanced and realistic fashion. The speed and transient accuracy is nearly on par with the world champion in this discipline, the Lyra Atlas. And there is more…..Air Tight managed to imply an oh so delicate touch of sweetness to the sound, which reproduces vocals in such an amazing way, that they will touch your heart an soul. This cartridge will transform your way of listening to music – because it does everything perfect and in a balanced way. It is not a specialist cart for listening to only classic music or Jazz oder Electro – no – the PC1 Coda is made for any musical style – which is very, very rare in todays high end market.

This outstanding performance lets me come back to the price of this gem….around €8000,- – which is everything than a special offer….but we have to think about that in a different way: Nearly all of us have more than one cart – because they all give us some special abilities which we like to hear mated with different music. A lot of us have 3 or 4 carts in their collection and maybe 3 tonearms to change them as the vinyl selection demands them….You already guess what I try to say??? – What if one cart fits it all – what if you do not need anymore 4 carts an 3 tonearms – what if you just need the PC1 Coda and a good Mono cartridge???? – If you share this point of view – €8000,- is not anymore as ridiculous as it seems to be – because you spent maybe even more money to own 3 or 4 cartridges, which are – that I can promise you are now obsolete!

If there is one really “complete” cartridge – it might be the Air Tight PC1 Coda – a deep bow to Miura San and Matusdaira san – you made it!

Stay tuned

E. Strauss

In the history of legendary tube constructions Amperex / Philips must be acknowledged as a forerunner in modern tube technology. Worthwhile to mention are the extraordinary frame grid Amperex 6922 (read pinched waist), the long Plates ECC83 and ECC82 as also the amazing Amperex 7316 to name just a few.

In this essay I will cover the 12AX7 and the 12AU7 Amperex Long Plates Foil D Getter tubes made in the mid of the 50ties (last century). These legendary tubes are nearly vanished from circulation – but if you have the chance to grab such a tube – DO IT!!!!! – nothing compares an Amperex 12AX7 Long Plates Bugle Boy oder the 12AU7 when it comes to render female vocals!

Why is this stuff so special??

If we measure different tubes in a given circuit with white noise and analyse the outcome with an Audio Precision System One frequency analyser we would not believe what we will observe. The difference in rendering a somewhat flat frequency spectrum from 30 – 20Khz is nearly negligible. One might think our ears poke fun at us – because we can detect tremendous differences if we compare different tubes of one type from different manufacturers, which are all differ in their construction not to forget the different materials which were chosen.

If I do a test with some people who are not into High End audio – and let them hear one specific piece of music with 3 different ECC83 /12AX7 in the gain stage of the power amplifier – all will agree on a different sound and nearly all of those probands will describe those differences in a comparable way. So what is going on….?

Our test method fails at this point – the sound difference of those 3 tubes is not so much in their frequency spectrum while giving them a static signal (white noise) – what changes everything is the dynamic behaviour of them! If we measure the reaction of the same three tubes to a short burst using different frequencies – the picture is completely different. Lets say we compare a Telefunken ECC83 Smooth Plates, a Mullard MC1 Long Plates and an Amperex Bugle Boy 12AX7 Long Plates (Foil D Getter) – we are in for a big surprise….

Tube compression

The Telefunken is able to render nearly the whole spectrum of short bursts without any compression – there is a slight amount of it detectable in the lowest octave as also some overshooting behaviour in the higher presence (around 4 Khz).

With the Mullard MC1 we have a complete different specimen, the Mullard compresses a broad section of the presence band beginning at 1,8Khz and reaching 6Khz. The character of the compression is comparable with tape saturation of our 1/4″ master tape recorder working with 19cm/sec. It is a compression character you cannot mimic with any computer plugin nor with anything else other than using a Mullard MC1. The bass as also the deepest frequencies near 20hz are rendered with a great openess and a very lively dynamic. In the deep midrange the Mullard overshoots slightly which gives this tube its sensational warm und 3D character in this frequency spectrum. The Mullard is about the deep midrange, about the base of the music, the fundament!

The Amperex 12AX7 Bugle Boy is the contrary of the Mullard MC1… The Amperex compresses the lower midrange, where the Mullard overshoots – and in exactly that frequency segment were the Mullard does its tape compression miracle the Amperex is completely open und highly dynamic – no other 12AX7 comes close in rendering the presence and upper presence in such a lively way as the Amperex 12AX7 Bugle Boy (the 12AU7 does this in an equal fashion).

Acoustic Sex

Micro dynamic shades are a kind of resolution we often forget but we must accept that this kind of resolution is very important – it makes us believe that the sound in front of us is real – micro dynamic resolution is the miracle behind a 3D rendering and makes us listening to music in an attentive way. The third dimension in a mix or mastering has nearly nothing to do with high frequency resolution or extension. If you want to prove that – buy some tickets to watch (and listening) an old black and white movie in a good cinema with a proper sound installation. What you will hear is a sound on film process, which has a treble roll off around 8Khz and it is mono – now listen to some of the great movies of the black and white era – and you will prove me right – you have every plane in the third dimension clearly displayed!

The Amperex 12AX7 (12AU7) Bugle Boy Long Plates can do this trick in the important Fletcher Munson frequency spectrum were our ear is very sensitive. Just plug such a tube in ONE single circuit position – lets say the one and only gain stage in your power amplifier and put on a record with a well displayed female vocal – lets listen to Ella solo with just piano…..every breath of her is right in front of you, every labial is rendered so damn real that you think she is with you in your room….The distance between the vocal and the listener is dramatically  reduced – you think you can touch the sound source….a very special experience! I call that acoustic sex….

Now you might think – hey give me more of that – and you use such Amperex tubes throughout any 12AX7 or 12AU7 position – and……it sounds like shit! Tubes like the famous Mullard MC1 or the Bugle Boy 12AX7 Long Plates are so special, that we can use them just in a small dose – we must use them as a top chef in its kitchen – a good meal is made of different spices mixed in a very distinguished way – and not in a fashion of  – one thing fits it all (hello –  do you have ketchup…..???)

The Amperex Bugle Boy 12AU7 Long Plates

With this tube we have one of the best options in the critical 12AU7 / ECC82 family….be it a phase inverter or a second gain stage – this tube will do a fantastic job. Especially in phase inverter positions this tube sounds amazing….and I know that you think – “it is just the inverter position” – the importance of this section implied in a push pull circuit is not widely understood! If your inverter stage is combined with the driver section for your power tubes, the Amperex 12AU7 is also a very good option which cannot be said of all European super – tubes….With a gain stage things depend on what quality you bought. As these tubes are nearly vanished from any selling platforms as also seldom offered by professional tube dealers, we often get used stuff – they are called “pulls”. Those pulls may be “lived” in an electronic gauge or some gear seldom used – but today heavily used tubes are often sold as nearly NOS… So we will have the same situation as with the Amperex 12AX7 Long Plates – we have to live with what we get….and normally those tubes are not anymore phono grade quality. That does not say anything about their electrical parameters, which might be very, very good….what I am talking about is microphony – and as both tubes feature long plates – there is a great chance that you will detect some microphony in a phono circuit or a line gain stage. It is strange, because a Mullard MC1 or the famous CV 491 (ECC82) are not prone of electromechanical noise – the Amperex is critical in this aspect. So in most cases we can use the 12AU7 Long Plates in a phase inverter stage – if we are lucky and the tube shows no microphony – do whatever you like to do – but keep in mind – the secret of tube rolling is in a balanced mix….

If we think it would be a good idea to pair an Amperex Long Plates with some of the legendary Mullard Long plates – it is not! Amperex long Plates needs something neutral sounding aside of them – so – you might guess what follows now….pair them with some nice Telefunken ECC83 – and you achieved a miracle!

The Amperex Bugle Boy 12AX7 Long Plates

The 12AX7 is as legendary as its stablemate the 12AU7 – it is an excellent option in an amplifier gain stage or line stage. As the microphony problems are much greater in the 12AX7 family of the Amperex long plates (because of much, much higher gain) the use in a phono stage would mean brad new real NOS stuff….if you find them – you are a lucky guy. However – in a phono stage a tube has a lot more to deliver, than just gain. If you put such an Amperex in your phono stage there might be some tube rush and the presence of clicks and ticks will drive you crazy. The Bugle Boy Long Plates are not as quiet as a Telefunken ECC83 nor are they so damn good in sending all the little nasties away from our perception. In other stages these tubes make much more sense – and will deliver an unforgettable sound. You get this sexy vocal performance and a sensational string tone which has a slight preference to the bow as to the body of a string tone. But its not said that the Amperex 12AX7 will have a weak bass performance – far from that. In fact this tube can deliver a very tight, deep and impactful bass with an amazing dynamic. The deep frequencies are rendered very fast and accurate while the midrange is fleshed out and very natural but on the more neutral (not tubey) side of warm. Because of the phenomenal microdynamic performance in the upper mid section as also the presence the Amperex sounds very meaty in this frequency range. These rich tonal upper midtone colours slightly prohibit a sort of airiness. The tube sounds not rolled off – but it is not the last word in airy sparkling treble performance – these frequencies are there – but a good portion is masked by the frequency spectrum right below the highest treble. From the upper midrange on you will detect a phenomenal richness in texture and tonal content. Amperex Bugle Boys are intoxicating!

The printing on the tube – or how to spot an original

These Amperex feature the famous treble clef comic printed on the glass of the tube. But there is a good chance that this printing vanished over time – those calc paint is extremely fragile – and often mess the printing up while  trying to liberate the tubes from their boxes. So how can we be sure, that we have an original tube in front of us….

There are some special traits we have to discuss:

If you observe the upper glas dome of the tube there have to exist 4 segments, divided by small glass ribs. The glas tube is thick and tall – if you compare it with a Telefunken you will discover how skinny the Tele is….;-))) The etched code must have the Delta / Triangle code of all Philips made tubes, and the plant code for Heerlen, because all long plates of these time were made in Holland. The inner structure features 17mm long narrow grey plates. The getter structure is very unique….it is shaped like a capital D with a big foil strip attached to it. This is the reason why tube freaks designate these tubes also as Amperex 12AX7 Long Plates Foil D Getter.

The same tubes are also in existence with a Philips logo printed on their glas – Amperex was a trademark found for the US American market by Philips – but it is just a trandemark – so there is no difference in sound nor in the built quality! Much later in the history of Amperex / Philips the latter installed production plants in the USA (Amperex New York) as also development departments, so there are pure US American Amperex tubes in existence which feature a different print and etched code. None of the famous long plates were manufactured in the USA.

As the American market was much, much larger than the European one – the chance to get these tubes with the Amperex imprint is much higher than with the Philips logo….in other words – the European market has nearly dried out! In the USA there is some stuff left – very expensive but if you ask me – it is worth the money and the patience to get those legends.

happy listening

E. Strauss

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 T27 tweeter

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 T27 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 T27 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 T27 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

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

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

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.

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!

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

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!

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

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 B110 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

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

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.

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 T27 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.

As KEF always had problems to produce the chassis, be it the B110 woofer or the T27 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

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

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 T27 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

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

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???

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

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!!!!

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