The famous 6L6 GC Powertube

The forgotten tube

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

This is completely wrong!

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

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 The tube was originally made for military applications and for that reason it is a very robust kind of a tube, the construction had to withstand a lot more when used in applications of the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

The Air Tight ATM4:


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

A living legend:


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

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

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


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

Tube rolling:

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

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


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

Signal flow and design:


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


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


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


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

How does it sound??


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

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


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

Classic design:


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

Some Tips:


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


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

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

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

Stay tuned

E. Strauss


High End 2018


Sometimes one could ask if an Ultra High End System is really made for the music lover – or if it is something like a Bugatti Veyron, a car with can deliver over 1000 PS (hp), wich needs an air break to reduce its speed within an acceptable distance and it is not able to be used in a fashion it was originally designed for – because the people who have such a thing normally do not own their own race track.

If you want to drive from A to B you will get into big trouble with such a “Super Car” – you cannot park the damn thing because you have an extremely compromised round visibility, the clutch is like a digital converter – on or off – and nothing in between – and if you have the typical stop and go situation, very common with todays traffic, it will over heat.

It is the epitome of idiocy! – But all your “friends” will be jealous because they think, that you could only take up the “super sexy” blonde sitting on the passenger seat with their impressive silicone artwork under her shirt, her sprayed lips as well as the nice Botox expression  on her face with such a monster car.

But be aware – great lovers do not need big cars…..

I listened to nearly every Ultra High End (read Bugatti Veyron) installation at this Munich High End show, and to tell you the truth, it was mostly disgusting, you had to leave the room just after a minute of listening, because the played music was extremely disfigured, the whole demonstration was not longer sustainable.

It is strange, that you have to spent several € 100 000,- to be rewarded with something, which can be so bad and ugly, that you will maybe shock your neighbour or some of you best HiFi friends with just the size and weight of such systems – but you can never  show them how your super expensive purchase will sound, which is in my book the purpose of such an Ultra High End Audio System….If you do so, playing some well known tunes with those monsterous Installations, you have a good chance to be capacitated by your family, friends and maybe by yourself….

I know, that a HiFi show is never a good place to judge the sound of a component or a loudspeaker, but I can differentiate what will be a problem caused by the given room acoustic and what a completely imbalanced sound reproduction in the whole midband will sound like. I do not judge the ability to show recorded space, nor the resolution a system is capable of – and of course below 80hz there is in most cases a more or less disastrous boomy reproduction common practice. But what I judge is the frequency spectrum from 150 – 5Khz – which is not so much affected by the room acoustics – it should be a very easy task to get a balanced midband reproduction in a price range of € 100 000,- but it is far from that!

It is interesting, that the real highlights of this years Munich High End show was none of the bespoke Ultra HiFi installations, you had to dig much deeper, and the findings were mostly very small companies, or not even that – sometimes it is just ONE developer with ONE product. The scene changed in the last decade dramatically, today real development (I mean development and not bigger, heavier, more expensive) occurs not necessarily in connection with big companies, or big money, more and more a different view at the topic is originated by “underground” developers.

Sometimes I thought that I was part of a TV – show like “The Hidden Camera” and in the next second someone would tell me, “hey this was just a prank” but the bitter truth is, there was no “Prank Patrol” (kids TV show), it was damn serious.

Maybe some rare examples of “Think Different” presented by independent, little manufacturers could give us back some faith in an industry which completely missed the warning shot.

Some of my personal highlights:

One of the best Step Up Transformer of the whole show was this thing here…. from Michael Ulbrich. The name “Monster Can” is chosen a little bit bold, but if you hear the performance, you will forget about the funny naming….


One of the most impressive turntables was  the L´Art du Son Transcription Reference from Martina Schöner. This machine showed most of the other installations, which often looked like the space ship of the “Borg” from Star Trek (Brakemeier Apolyt), how awesome pitch accuracy, weight and speed as also agility and neutrality will sound like! A dream! And yes, it is very expensive, but it was in my book the only very expensive deck, which had something like a realistic price performance ratio.


One gets confused, when a broadband loudspeaker chassis from the 30ties last century was one of the highlights of the whole show – in this case the legendary (rightly so) WE 755. Truly amazing!!!


Another great example of a very good turntable setup was the Thomas Schick 12″ tonearm combined with a Garrard 301 and a Vinylista plinth.

Something most people are not aware of – the Schick 12″ with the Grafite headshell can handle a very wide range of cartridges – and not just an Ortofon SPU or DL 103 – in this case, the arm is fitted with a Van den Hul Colibri. A cartridge which is not an easy task for a tonearm, often this little “bird” can sound very forward in the treble section. With the Schick 12″ arm the sound was very balanced!


Frank Schröder showed his latest tonearm creation the “Broadcast Arm”. It is a stabilized uni pivot design with a variable effective mass (13 – 23g). Frank mated the “BA” arm with a Miyajima cartridge, and the sound was sublime. An outstanding combination!


The turntable Frank used, was a fully restored and modified Gray Research HF 500. The sound was very detailed and natural with a bold colourful midrange and a fantastic drawing up of speed accuracy and an agile renedering of the leading edge as also a superb sense of three dimensionality.

In combination with the BC arm one of the very rare decks which could deliver a sound reproduction, which was amazingly real!


The chance to listen to an original Western Electric London Horn was assuredly one of the highlights in Munich. The whole system had a slight colouration in the range of around 580 – 800hz, it was a touch too forward in this frequency spectrum, but if you once got used to it, you were in for a real treat in the dynamic compartment. Maria Callas with one of their amazing arias from Giuseppe Verdi was so intense, so real and so emotionally touching, something at this sensual level you would hardly find with any other installation at this audio fair!


It was completely amazing, to realise that in the 30ties last century the audio industry was able to create a kind of sound, which  reproduceed music in such a realistic and touching way.


Sometimes I think it can´t be tue, that with all the computer power, the modern techniques and all the “high tech” we have available today , everything we can do is delivering some real torture, we could find in most of the so called “Ultra High End” rooms.


A side aspect of such an audio fair is also the product design we have to face today – form follows function is not modern anymore – today the designers have no more ideas, and therefor we have a lot of products, which could be probs of “Star Wars” or”Alien”.  Sometimes it is embrassing and sometimes you have to lough, it is probably the same situation which we can see within the car industries design departments – I mean – do you think a Toyota Prius is really beautiful and an example of outstanding design??

This I would call a classic design…..


Silbatone amplifiers are maybe one of the best money can buy. They are manufactured with special in house wound silver foil transformers and are designed with very special and distinguished circuit principles. They use throughout the finest NOS tubes of the audio history as also very good components from suppliers like Silvercore or Dave Slagle (Intact Audio) to name just a view.


The amazing WE London Horn System…..


A very discrete “branding”….;-))) seldom seen at this show.


Stay tuned

E. Strauss

What a feeling…..Part II Ortofon SPU Royal N


In Part I of the SPU story I gave you an overview about the history of the Ortofon SPU and the technical aspects to use one of these classics within your stereo system. In this episode, I want to give you a specific view of one of the many different types Ortofon has to offer, the SPU Royal (N).

A kind of blue


The SPU Royal N differs in some specific design aspects from the SPU Classic and its stablemate the Classic – E (elliptical stylus). First of all, Ortofon uses with the Royal version a special stylus, which they call Replicant 100, a derivate of the common line contact stylus shape. With the implementation of such a “modern” shape Ortofon managed to reduced the moved mass of the stylus tip, because the Replicant stylus carries nearly 50% reduced mass, than its opponent used in a SPU Classic. Reducing the mass within the moving parts of a cartridge results in betters tracking performance as also the ability to follow the music in a more immediate way. The leading edge will be rendered in a much more accurate way as it will be also the case with the presentation of micro dynamic shades of our most demanding vinyl records.With reducing the moved mass of the Royal (N), Ortofon  was able to design a slightly different suspension system, wich results in a decrease of the recommended vertical tracking force from 4 – 5g to “just” 3g. The coils of this cartridge were also modified, a hybrid construction made from gold plated silver wire is used, and therefor the internal resistance of the SPU Royal changed from the 1,5 – 3 Ohm resistance of the traditional SPUs to 6 Ohm in the Royal (N). With a 6 Ohm internal resistance we do not gain any increase in output level, the Royal produces the same 0,2mV as the Classic or Classic – E would do.



The impedance change up to 6 Ohm has some consequences in considering the use of a step up transformer (SUT). With the traditional SPU cartridges we use a 30:1 SUT  and will get, around 29db gain with such a device. The 30:1 SUT is virtually made for the Ortofon SPU range of cartridges – but those traditional SPU carts share a very low impedance of at most 3 Ohm – and only with this impedance value our SUT will deliver those 29db of gain.With the 6 Ohm Royal (N) cartridge we will face a lower gain value, because of the doubled internal resistance – the 30:1 SUT will deliver under this circumstances something about 27db (impedance mismatch) which results in a serious drop of gain. And to make the things more complicated, Ortofon recommends with the Royal (N) a load impedance of 100 Ohm instead of 50, the latter will be the optimum load for a SPU Classic.

A 30:1 SUT is not the best match with the Royal (N). If we look at the technical specs of a 20:1 SUT, we realise, that such a SUT will be a much better partner for this modernised version of an old classic. The 20:1 SUT gives us 26db and the cartridge will “see” 117 ohm load impedance which is exactly, what we need. In terms of gain, and load impedance. We achieved now a perfect match but we have to face the fact, that we still deal with a 0,2mV cartridge which will be decreased in gain about 3db in comparison with a 30:1 SUT and the SPU Classic series of cartridges.

Lets calculate that:

Example 1: SPU Classic, 2 Ohm, 0.2mV, recommended load impedance 50 Ohm 30:1 Step Up Transformer

Input:         0.2mV

Gain:           29db

Output:       5,64mV

Example 2: SPU Royal, 6 Ohm, 0.2mV, recommended load impedance 100 Ohm

20:1 Step Up Transformer

Input:         0.2mV

Gain:           26db

Output:       3.99mV

P1050161 (1)

This little gain calculation clarifies different technical requirements for both types of SPU cartridges , if we want to use a cartridge like the SPU Royal N, we must have a phonostage which is able to compensate for the lower gain values we will get with a 20:1 SUT. As most of the SPU aficionados will use a tubed phono stage, you will have to verify the technical specs of such a device – everything less than 43db is not suitable for the SPU Royal (N).

Lets do some math again:

Example 1: SPU Classic, 2 Ohm, 0.2mV, recommended load impedance 50 Ohm

Output:       5,64mV

Input:         0.2mV

Gain:           29db

Output:       5,64mV

MM Gain:  43db

Total gain: 72db

Total output level:ca. 0,8 V

Example 2: SPU Royal, 6 Ohm, 0.2mV, recommended load impedance 100 Ohm

20:1 Step Up TRansformer

Input:         0.2mV

Gain:           26db

Output:       3.99mV

MM Gain:  43db

Total gain: 69db

Total output level:ca. 0,5 V

L1004397 (1)


Both values are under 1V, which would be the gain level of a FM tuner, in comparison a CD player will deliver an output level of 2V if it is made with the Sony/Philips specs once adopted.

And in case of the Royal (N) we will get only 0,5V which is half of the output level a FM – tuner is able to deliver. Now you will understand, why a line preamplifier is indispensable teamed up with a very low output phono cartridge.

Lets assume our tube power amplifier will handle 1V at its input for delivering its maximum output power (a very common value), than the signal we will feed in our line stage is not high enough in both calculations shown above to reach the headroom of our power amplifier, the line stage has to provide additional gain to reach a value of 1V.

With todays CD players, which often produce an output level of more than 3 or 4V, our line preamplifier is degraded to be a very expensive attenuator (In a later article I will describe that subject in depth)! But everyone should understand now, what the purpose of an active line stage originally was – this thing had to give us additional gain, as it was also designed to bring input and output impedances to common values, compatible with our source devices as also our power amplifiers!

And the sound??


As we realised with using the Ortofon SPU Royal (N ) we have to meet some requirements prior of use – a 20:1 SUT and a phono stage capable of delivering a minimum of 43db of noise free gain in a moving magnet configuration.

If both requirements are met, we will get something very special….this is not only the traditional SPU sound, there is a lot more to discover. The Royal (N) will bring to the table an increased resolution as also a refined tracking performance. It has still the bolt and holistic sound we adore so much, but the cartridge is able to show you a lot more resolution as also a better understanding of the micro dynamics of the recordings. The resolution is on par with a lot of super modern constructions but lacks to end in itself. The resolution is given to you in a very charming and smooth way, there is no shining light on this aspect of the sound reproduction,

The tracking performance is superb – the most demanding cuts are played with no hint of a grain or the slightest roughness, Ella Fitzgeralds most frightened vocal performances are shown in such a relaxed way, that you will be stunned. The ability to show us more pin point accuracy in terms of reproduction of recorded space is on par with some very good high tech carts out there. The Royal (N) is something like “Two Face” in the famous Bat Man comics. There is the classic SPU sound in its full glory, but on top of that you get a higher level of performance, and sophistication normally associated with modern high end cartridges. The Royal (N) is maybe the squareness of the circle, on one hand there is the smooth and holistic gestalt of the classic SPU, and on the other hand, their is a good portion of modern aspects which are not a betrayal of the original sound.

A great opportunity to dive into the culture of the oldest of all moving coil cartridges, a true classic slightly modernised – a masterpiece – thank you Ortofon!

Stay tuned

E. Strauss

Jan Allaerts MC1 Boron

Belgian chocolate candy

Jan Allaerts is a cartridge master builder from Belgium.

A Legend in the history of High End audio!

As Belgian chocolate candy and other world famous sweets from this little European country, the Allaerts cartridge is wrapped in a very noble golden outfit, packed in a sort of chocolate or jewelry box. The beautiful appearance is just the foretaste of what you can expect sound wise….

To listen to such a rare audio exotic is for most of the audiophile world something which is seldom possible, because Jan has a very limited production output (he builds every cartridge by hand), and therefore those cartridges are not widely spread in the market. If you once listened to a cartridge like the MC1 Boron or even a higher classed moving coil out of his workshop, you will never forget that experience – and you won´t sleep till you have one for yourself…

Looking closer

P1050778 (1)


The technical data Jan publishes on his webpage is in some aspects hard to believe. You will find informations about the tracking ability of the MC1 Boron which tells you, that 200 mü/mm will be possible and also the channel separation of 50db at 1 Khz is a figure seldom seen in this context. These superlatives would not mean, that such a cart would sound exceptional, but I have found nothing comparable with any other cartridge manufacturer – and if you talk to Jan, he is rooted in the soil and not one of these braggarts with are not so rare in the audio scene, instead you have a very modest person in front of you.

Jan Allaerts MC1 Boron MkII Cartridge

The MC1 Boron has a motor unit which is based on an EMT developement – Jan modifies this classic in every aspect except the internal resistance of around 20 Ohm per channel (the original EMT has 20 Ohm, Jans self wound coils have 22 Ohm internal resistance). The cartridge uses a boron cantilever which is equipped with a Geyger special polished diamond tip. The coils are hand wound using incredible fine wire on a 2mm x  2mm soft iron square. The basic housing is made of solid brass wich is completed with a 0,3mm thin brass cover coated with a 24ct gold foil. The latter acts like a Faraday cage! In opposite of what some very “experienced” high end freaks will tell you – let the case were it belongs and do not strip the cartridge down – I know something naked has its charms – but not in this case….;-)) Jan uses 14kt massive gold connection pins – which is as far as I know unique in that area and guarantees a perfect contact between your tonearm – wire – plugs and the cart itself.

Jan Allaerts did a lot of research in the field of the molekular structure of different materials and found out that material wich is not stressed during its manufacturing process makes it a better electrical conductor. The pole shoes of the magnetic circuit are handmade to avoid any changes in their molecular structure and Jan uses rare earth magnets (Alnico) which are rechargeable if after a long time of use, they once loose their magnetic energy.

As you might guess the attention to every single detail is unbelievable – Jan must be a perfectionist in its purest form!

Matching with a tonearm


The cartridge has a compliance of 12cu, which means that you need an arm in the so called medium heavy class – which meets the specs of most of what is on the market today. That does not mean that every tonearm in the medium heavy class is appropriate to get the full performance which this cart is capable of  – far from that. If you google Jan Allaerts cartridges you will see a lot of illustrations showing an Allaerts matched with a tonearm from Simon Yorke or Frank Schröder.

As I own a Schröder Reference it was a logical consequence to pair this arm with the MC1 Boron – actually the presence of the Reference arm was my inducement to get such a cart….. My Reference arm has a effective mass of 13g with the usage of the “Certal” (special aluminium) headshell plate which is in terms of the effective mass a perfect match…

I think Jan uses beside Simon Yorke tonearms also the SME Series V to develop his cartridges, so this tonearm will be also a great opportunity to listen what an Allaerts cart has to offer.

The MC1 Boron needs a very precise VTF (Vertical Tracking Force) adjustment – Jan pretends you just a range of +/- 0,1g – which makes the usage of a digital gauge and some endurance indispensable! The VTA (Vertical Tracking Angle) should be set at the beginning in a way that the top of the cartridge will be set parallel to the record surface – from that point on there might be small – or better –  very small corrections necessary – the MC1 Boron reacts very sensitive in that regard!

If the sound tends to become some glare, you have to adjust the tail of the tonearm slightly down – if there is too much “bloom” in the upper bass and midrange, the armwand must be slightly raised.

A good sign that you nailed the sweet spot is a wet, smooth and extremely detailed treble performance with the absence of any harsh sound artifacts a pinpoint accuracy in rendering recorded space as also a very, very natural reproduction of the human voice.

The cartridge should be used with 100 Ohm termination with an active phono stage and is also a fantastic match to a 15:1 step up transformer. Both possibilities sound somewhat different, with the usage of an active phono stage you will get a more spacious and open sound with tremendous dynamic abilities together with a bass punch which is terrific. As the output of the MC1B gives you a very healthy signal of 0,5mV the usage of a step up transformer is not essential – you will gain with a step up transformer a better wholeness of the music, but you will loose some of the dynamic abilities and also the delicate openess will be restricted.

As I am a big fan of using step up transformers together with moving coil cartridges to maintain enough noise free gain, I would give preference in this case to a full active phono stage. In my setup I use an Air Tight ATE 2005, which offers on one of its three phono inputs a Class A transistor headamplifier, which is fed into a full tubed MM stage, a very nice combination!



As the Frank Schröder Reference tonearm has not a fixed headshell / azimuth as an SME series V, you have to dial in the correct azimuth whenever you change a cartridge. To explain the adjustment of this very, very important parameter we will use a record with a vocal performance placed in the mono center of the stage. A good help will be strong produced sibiliants on that record.  A perfect aligned speaker system and good roomacoustics is a must in this case, also you should place yourself exactly in the sweetspot of your speakers. Start the adjustemt using a gauge, which is normally a plexiglass block with engraved parallel lines on it – place the block in front of your cartridge and drop the needle on the naked platter or the record surface. If your platter has a slight bowl shape – this method has to be refined – in this case you need a piece of thin glass (the makeup mirror of your girlfriend or wife comes on handy…..;-))) which reaches nearly from the center of the platter to its outer section.

Now use a good magnifying glass (I use one which is made for watch makers) and get a fix on the horizontal planes of your cartridge. If that is not precise enough, use a pencil mine, which you have to place on top of a horizontal aligned part of your cart – look again through your magnifier – every little variation is now easy detectable!

Adjust your azimuth accordingly!

If you finished this basic adjustment you ave achieved an azimuth of 0° – if the stylus is perfectly aligned you are finished know – if there is a slight offset implemented with your cart, you have to listen carefully… A wrong azimuth adjustement is clearly detectable – you get sibiliances of the human voice wich are not anymore placed in the mono center, they will move very, very fast between the channels – reverbs, which are isolated (last snare drum on a ballad for example) do not vanish symmetrically – and the whole sound is comparable to an out of focus camera lens . A good sign, that the azimuth is not correctly adjusted is also the achievable quietness of the cartridge tracking the grooves. If you will detect an abnormal raise in the noisefloor, it will be a good sign that your azimuth adjustment is not spot on. Adjustemts have to be made in tiny steps – so, please be patient – azimuth adjustments needs a lot of time, and some experience.

Another possibility is to measure the correct azimuth – for that you need an Oszilloscope in X/Y depiction and a very, very good produced test record (Ortofon 001).

I am not a big fan of software based systems – because these have to deal with the sound card of your computer – if you do not spent serious money to get something professional, you have a measurement system equipped with minijacks and computer based AD converters.

If you spend serious money and you have a good sound card which is calibrated, you could use a professional Hard Desc Recording software as Avid Pro Tools – with the software package comes a bunch of measurement tools, which are able to detect the phase relationship between both stereo channels.

But at the end a pair of good ears is never a wrong way;-)))

With the MC1 Boron I was finished with adjusting the cart at 0° azimuth offset – this thing is perfectly build!


The sound experience


Put a vinyl record on your platter with some natural instruments recorded in a real space like classical music or Jazz. Drop the needle into the groove and you will get a soundstage,  a size of the reproduced music, you will never forget. If I had to crown the king of sound stage reproduction – it would be a Jan Allaerts cartridge! It is not just the width of the virtual stage – there an Ortofon SPU performs also in a very special way, it is the space which will be reproduced in all three dimensions. The ability to show the depth of a concert hall is so special, that you will listening to well recorded classic for the next months!

Every instrument seems to be not a point on the stage instead you will hear a three dimensional event, if you close your eyes there is  no localisation of your (well placed) speakers possible anymore  – a miracle. But there is more….

The Allaerts cart has the ability to reproduce the dynamic swings of the music in a way, which is not far away from  legendary DECCA London cartridge (another story….), it can produce the finest dynamic shades as it can deliver the big picture in a enormous way. The MC1 Boron can be brutish as well as smooth and tender in a fraction of a second, it can reproduce the dynamic shades in an instant, the speed of that little golden HiFi candy is outstanding.

But if you think now – ok, that  sounds as if an Allaerts cart will be an anlytical and ultra precise piece of equipment – you are not totally right – because the MC1 Boron has a type of a velvety performance which is hard to describe. The basic gesture of this cart is neutral – very neutral – but there is a oh so slightly smoothing at the top end and there is a very, very little emphasis in the midband which is a tiny portion of 1 db in terms of gain – but the Q of it is very broad – you will not face a shining light at a small portion of the midband – it is the whole midband which is affected in a very sensitive way. The Bass performance is also one of the best I have ever heard – it is not the heavy hit, you get with a My Sonic Lab cartridge nor is it the punchy style of an EMT JSD5, it is all together dressed in a fine Giorgio Aramni suit.

The three dimensionality  of the MC1 Boron is sometimes spooky, it has the ability to display sound sources far away from the point were your speakers are located, this ist true for the width of the stage as also the depth. If you listen with your eyes closed, there might be a good chance, that you sometimes think something or someone is with you in your listening room. The palette of shades the Allaerts MC cart can produce is so colourful and saturated, that, your brain does not have to abstract from the instruments or vocals to accept the reproduced sound as something real.

If there is one section were we can find a small foult it will be the quiet ride in the groove – the Allaerts is not the pinnacle of what is possible in this regard, it shows you clearly the state of your vinyl collection, so a proper vinyl cleaning machine is welcome. For such a highly detailed cartridge this small restriction must be accepted.

Is there something comparable to a Jan Allaerts cartridge?? – I am afraid it is not….It is no surprise that these little gems gain a legendary status in the ultra High End scene – it is one of the best MC – cartridges, money can buy!

As Jan Allaerts rebuilds used cartridges to their original specs, which means retipping, a new cantilever and also recharging of the Anlico magnets – your journey to an Allaerts cart could start with buying one in the used market, but be sure it is in its original state, because Jan denies any inquiry if the cart is modified in any way, which is something I can perfectly understand! If you want to have ONE super cartridge, a Jan Allaerts could be the end of your search, it does not have any favourite discipline, it can rock, swing, and boogie it will give you some unforgettable moments with classical music or Jazz as it can give you goose bumps while listening to a well recorded vocal!

Stay tuned

E. Strauss



Listening to a monophonic record

A lot of great music was delivered before the year 1958 were the first stereo recordings appeared on the market.

Most of the great Beatles songs were mixed in Mono – and the Mono mix – sessions were the really important ones in those days – the artists and the producer took great care to deliver the finest sound they could achieve, the later made “pseudo” stereo mixes were not so inportant, and often done without the artists or the producer witnessed that procedere.

If you ever compared John Coltranes amazing  „Blue Train“ (Blue Note 1577) in the original Mono pressing with their Stereo counterpart on a proper built monophonic sound system, you will be shocked how much better the mono pressing will be!
Some of the most respected Jazz recording catalogs at this time, like  “Blue Note“, “Prestige” or “Impulse“ to name just a few, originally were produced in Mono!
Some of the most beautiful recordings of Maria Callas were – you guessed it – also done in Mono.
And if you ever want to discover amazing music the great Toscanini conducted long time bevor Stereo was invented, which set the standards not only in its days – you will face a Mono vinyl record.
A list of all the fantastic music captured in Mono could be endless, and I can promise you, there is a lot of amazing stuff to discover, you are in for a real treat!

So a dedicated Mono system is not something for completely outdated, crazy freaks, to have the possibility to listen to a mono record in a technically correct way has something to do with loving music, overcoming the ignorance that there was a world of fantastic recorded music in existence before Stereo was invented.

A Mono Setup


As the Quad ESL 57 was originally designed to listen to Mono recordings, because Stereo wasn´t invented in those days, also later on it was not very spread at first, it will be a great opportunity to built an outstanding mono system with this first commercially made electrostatic speaker.

if you use monoblock amplifiers,the modifications, which have to be made are very simple  – put one amplifier on the side, as you have to do so with one of the speakers – and you are done.
If you use a stereo tube amplifier, things are not as simple, because tube amps do not like to be operated without any load at their speaker terminals existent, which will be the case if you use just one channel. There will be a great chance to destroy the output transformer of the bespoke channel.
The solution is the usage of a dummy load, which is implemented by a resistor of 4 – 16 Ohm capable to withstand enough wattage, which simulates to the amplifier the load of the missing second speaker in our Mono set up.
Some stereo tube amplifiers can be swithed to mono operation, normally used to get more power from them – so great care has to be taken not to overload our electrostatics (keep in mind – 33v is the absolute maximum these construction can handle) but such a mono cunfigured amplifier will make things very comfortable and easy.
Place the ESL exactly in the center of your speaker base in your room with the same distance to the rear wall, and a symmetrically position to the side walls, you have found to work at great effect with your stereo setup and you are able to enjoy amazing monophonic recorded music reproduction.
If your your preamplifier has a Mono switch – and you are not willing to do all these modifications to your stereo set up, even if it is not the most puristic way, you can let your normal setup untouched – and listen to a monophonic source with two speakers.

However – one thing is essential, no matter which monophonic configuration I described you choose – and this is the presence of a dedicated Mono cartridge!

A dedicated Mono cartridge


Now things get again a bit more complicated, because the stylus of a real Mono cartridge is only sensitive to movements in the horizontal plane, as Mono records are not being cut using  the 45° technique invented with the Stereo process to encode the two channels.
Any cartridge, which is in effect a Stereo cart modified by the manufacturer with a kind of Y connection at their output contact pins, will deliver a noisy, smeared sound, used with monophonic vinyl which gave Mono records its bad reputation.
A true Mono cartridge has a dedicated suspension optimised for monophonic records and is not simply a modified stereo cart – so most of the “so called” Mono carts are not what they pretend to be, because the manufacturer has to invent a complete redesign of their suspension system, which is a much too expensive development for most of the participants of that industry, as the expected sales will be much lower as with a normal Stereo cart.
One of the truly outstanding manufacturers for a real Mono cartridge is Miyajima Labs  from Japan.
Beside their amazing Stereo cartridges these manufacturer has developed a range of real monophonic pic up systems, which are top notch.
The pinnacle of the range represents the Miyajima Zero – a cartridge which has a real monophonic suspension system and is created with the usage of African blackwood on its body. This exotic hardwood gives the construction a very good energy absorption capability, helping our tonearms to deal with the mechanical energy sent from the cart into the armwand.

A word of warning must be mentioned here: Keep in mind, that a monophonic cartridge used with a Stereo record will destroy the latter, because the suspension is not able to follow the stereo – cut!

Electrical connections



The Miyajima Zero is equipped with 4 contact pins at its back, which makes the installation in a normal Stereo tonearm very easy – no cables have to be dropped or taped together to avoid hum or, much worse – get in contact with the record surface.
The cartridge has 6 Ohms of internal resistance and an output of 0.4mV both figures are not exotic and compatible with a wide range of phono stages.
The use of a step up transformer is very much appreciated, it gives the sound a certain wholeness and a very nice sparkle at the top end of the audio spectrum, as also a fantastic bass performance.
A good SUT will be a 1:20 type which will produce enough gain for the following moving magnet phono stage.

If you want to touch the 100% mark – do yourself a favour and use a tube driven phonostage – the possible sound quality will be amazing and also the historically correct way to listen to our favourite monophonic vinyl records.

Mechanical basics



 The Miyajima Zero has a compliance which is comparable with an Ortofon SPU – so a heavy tonearm is essential.
The starting point will be something around 20g eff mass – and as it is the case with the Ortofon SPU, the best performance will be reached around 22 – 24g!
If the tonearm is too lightweight the sound will become nervous and thin, the stage will be smeared and the impact in the bass frequencies is compromised.
With nearly all my vinyl – rig setups I made the experience, that  if the resonance frequency of the mounted cartridge would fall into the range of around 9hz, a good mechanical isolation of your turntable provided, you will get a very balanced overall performance.
The tonearm which guides the Miyajima through the grooves should bring along a very good ability to deal with mechanical energy wich the cart sends into the armwand – even if the wooden body helps here, the Miyajima is not an easy cartridge in this area.
Undamped steel armtubes, which we can find in the legendary first series of the SME 3012 are not a good choice in this case, the sound will be harsh and abrasive, a good damping is essentially with the complete range of MIyajima carts, will it be a Mono, or the very special built Stereo models.
I use my Zero cartridge with a Frank Schröder DPS custom made tonearm which implies a snakewood armtube (22g eff mass), that shows an outstanding performance with this cart.
The reason for the great compatibility is Franks patented magnet bearing which has the ability to dampen the cartridge with a fine adjustable induction of Eddy current at its bearing.
A Thoms Schick 12“ or 9.6“ together with the new Schick graphite headshell, Thomas recently invented, will be also a fantastic setup!
Both tonearms can handle the Miyajima carts in an outstanding way – one could think they are made for each other!





 The VTF must be set at a frightening 3.5g – but stay cool – your mono records will appreciate it and in contrast to some high end rumours, these vinyl records will outlive you and your children!
The VTA should be adjusted in a way ,that the top of the cartridge body flush with the record surface, from that point on, some experimentation is necessary.
Listen to the human voice and the presence of it. If the treble reception (S, T, SCH) will be slightly localized in front of deeper frequencies, you are done, if the presence will be at the same position as the deeper frequencies, the VTA must be adjusted, so that the back of the arm has to be raised slightly. The goal is, to reach a natural reproduction of the human voice, in wich treble, presence and the deeper midband are balanced.
You will incedently know if the things begin to lock into place – some effort at this point will be the ticket to a completely satisfying listening experience!
Antiskating should be adjusted in a way, that the cart cued up in between the groove at the end of the record, will slide gently towards the label with the same speed as the groove.
It might be a slight under – compensation, but that will be much more appreciated than the opposite.
The Zero is capable of such an outstanding performance, that if you are not satisfied, the reason must be searched somewhere else in your setup – some minor adjustments will have a great effect – so be patient!
The Miyajima Zero has the ability to give you such a high performance in every aspect of the typical audiophile parameters, that listening to Mono pressings will be a thrill!
The punch and impact those records will have is amazing, and the presence of the sound is something you have to hear yourself to believe it! Mono is not for people, who cannot afford stereo, Mono is something very special most of us have long forgotten!


The needle – make your choice



Miyajima Labs gives you the opportunity to choose between three different stylus tip constructions.
There is the 0,7mil sized tip, which is the optimal choice for those of us, mostly listening to Mono reissues.
Than there is the ability to use a 1mil tip, which is the way to go, if you have a great collection of antique monophonic records from the 50ties.
And for all 78rpm lovers Miyajime offers a 3.0mil Shellac compatible cartridge – but keep in mind, that vintage original pressings (33.3 and 78 rpm) are normally not cut with the RIAA curve implemented (a technical standard later was invented) – so you need a special phono preamplifier with the opportunity to chosse different deemphasis curves!
One of this rare units is the Sentec phono EQ unit made in Sweden – with this device you have the chance to dial in nearly every deemphasis curve the different record company used in those days. The specific deemphasis curves of the different record companies used in the “pre RIAA” era is a story, I will write about in the near future – so, stay tuned…..
If you want to have the things more comfortable – use the modern reissues – and enjoy some great music.


Listen to some music



One of the best addresses for amazing good mono cuts is the US American company Acoustic Sounds, Chet Kassem (the owner of Acoustic Sounds) is doing a fantastic job in remastering those  old recordings with the assistance of some of the best mastering engineers in the world.
The pressings are very quiet, you can count the ticks and crackles on each sind with the fingers of one of your hands – truly outstanding.
Chet did in the last years a lot of remastering work with some of the legendary Mono cuts from the famous „Prestige“ catalog – so you are able to listen in 2018 to a cut originally made in the 50ties showing the early work of Miles Davis or Eric Dolphy!
The Miyajima Zero is riding the grooves of this fantastic made Mono reissues in a way that is jaw dropping. Out of a jet black backgound you will get an amazing amount of macro and micro dynamics which could be frightening, this little gem produces a sense of presencem which makes the whole performance sounding real and authentic. And you wont believe it – there is a sort of space and a three dimensionality in those recordings, which is technically not possible, but it is there.
The bass section is so bold and tight, with so much articulation in the deep spectrum, that you will jump out of your chair – the realistic representation of the music is so touching, that you wont miss the huge stage a Stereo record is capable of.
Mono can be an eyeopening experience!
The musical performance is presented in such a pure and immediate way, that you will be really touched, it moves you in a very special way.
If Maria Callas is performing one of her famous pieces from the Aida opera recorded in 1951, it might be impossible to hide the tears in your eyes!
Much fun with MONO
E. Strauss

What a feeling…..the Ortofon SPU

Some thoughts

During the period of 1957 – 1959 Robert Gudmandsen invented the legendary SPU (Stereo Pick Up) moving coil cartridge for the Danish company Ortofon. The typical customer of that day was not the HiFi enthusiast, it was the professional broadcast industry which used this cartridge for their on air music program.

In 2018 you can still buy this cartridge – 61 years is close to an eternity in the entertainment electronics industry. And in spite of all the inclinations, it is not a dead product for some wise, grey, old men with their vintage gramophones – generation after generation there is a still growing number of audiophiles, who will sooner or later discover the sound of an Ortofon SPU.

Old versus new


There must be a certain fascination listening to your record collection using this legendary vintage design, otherwise this long lasting popularity can´t be explained. Today a growing market is the Far East – and to tell you the truth, the Japanese audio enthusiasts were always ahead of their time, otherwise it can not be explained why the Japanese High End scene was the first to rediscover the Single Ended Triode amplifiers or Western Electric horn loaded speaker systems, which the American scene thought were a load of scrap metal in those years. And even we German enthusiasts discovered the fine quality of professional broadcast equipment, like the EMT 927 and 930 as well as Studer CD players to name just a few, long after they were hip in the Japanese scene. With South Korea it is now the same story – or do you remember any better sound demonstration at the last couple of audio fairs in Munich, than those carried out by Silbatone together with their huge Western Electric installations?

By the time we muzzy European audiophiles got it, the prices had gone up to stratospheric regions or the cool stuff had vanished from the market and was in solid collectors hands! Indeed most of the “scene” here believes, that newer is always better, and more expensive is a guarantee to get the best sound – so they will never realise that in some areas of our beloved hobby, the peak performance was already reached a long time ago.


How else can we explain the intoxicating sound of an original Wesetern Electric 300b engraved base – a tube which is today not rare, it has vanished completely from any circulation on selling platforms – and you might guess who on this planet has a stash full of them???

Until today it seems to be impossible to build something that equals the sound of this tube legend. And the younger audiophiles among us, just as the modern tube industry, who both eventually never had a chance to listen to the original WE 300b engraved base, won´t get tired of telling us that a modern 300b of the brand “xyz” can match the sound quality of the old American tube… Friends – that is a fairy tale until today!

So, it is not a bad idea to look at Japan or South Korea and also China, if we want to get an idea of the latest fashion in High End audio! That makes us vinyl junkies who were yesterday old fashioned and behind the moon, today, the latest fashion. We are now hipsters!!

Apparently those people in the Far East have a better understanding of sound and the beauty of it, and they might have a better understanding of traditional and modern culture and how to bring both things together??

Maybe there is a reason, why the legendary Ortofon SPU is so popular in the Far East and maybe we should get in touch with this all time classic!

Restoration job


I discovered the Ortofon SPU 20 years ago, having a job project were vinyl restoration was implied. I had an assignment to digitise (oh yes, I know that is hard stuff…)  1200 vinyl records for a German archive. The records were all together in a mediocre shape – after endless cleaning processes with professional record cleaning machines, I found out that a modern high end cartridge with a compliance of around 12cu or more, will lengthen a scratch on the vinyl surface on the time domain. The scratch is not anymore as long as it is, there is so much energy traveling up the needle and tonearm, that the scratch has nearly doubled its length on the timeline. This means that later applied interpolation algorythms of my Sonic Solution workstation had to do a much tougher job to get rid of the scratch and bring on the original modulation at the given timecode address.

What to do….??



One day – when I was close to a nervous breakdown, I discovered the history of the moving coil pic up – it was a sort of skipped action, because I had no further idea how to bring a proper signal to my DCS AD Converters to get the most out of the scratched vinyl surface. And as you already know – I stumbled upon the Ortofon SPU…

20 years ago you were a nutcase if you entered a HiFi shop asking for an Ortofon SPU – and so I had a long discussion with the gentleman behind the counter, who wanted me to buy a Van den Hul DDT instead of a SPU cartridge. But I was steadfast and ordered an Ortofon SPU A with an elliptical stylus.

Weeks later I got the vintage cartridge and mounted it on my EMT 997 tonearm. And guess what – the beast sounded wonderful – and it made out of a scratch what a scratch really is – a short spike and not a huge monster! After the job was done, I had heard 1200 records with this thing – I mean for a very long time I had listened to nothing else than an Ortofon SPU. As I was finished and felt some passion to listen to my own records at home again, I was not prepared for a huge surprise – a sort of cultural shock.

My cartridge at this time was a a Dynavector Karat, which I loved very much. The Dynavector had so much more surface noise and told me about every scratch on the vinyl surface as a racing car would do with the given road conditions. But that was not everything, there was a cut in the midband of this cartridge, a treble rise and a thin bass. From that moment on, there was a SPU in my home at anytime!

The Tonearm


To dive into the world of an Ortofon SPU there are a lot of requirements necessary to bring out the full potential of such a cartridge. The first thing is a proper heavy tonearm. That might be one of the biggest challenges, because in our modern HiFi market such tonearms are nearly forgotten. If you do not want to use a 12″ arm, the problem to get an arm with a high effective mass is even more difficult. The candidates are mostly vintage examples, which we can get in the used market with some luck. Think of an Ortofon 309, Fidelity Research FR64S or 66S (12″), or the SME classics 309 or 3012 – both of the latter have to be the first generation of this classic. But if you discover these vintage warhorses,  there are some problems you will find, which nobody is talking about.

The FR64 and 66S – both are among the best tonearms ever made using steel for their armtube – do not sound especially good with such an SPU cartridge – do not ask me why, such FR arms matched with a Koetsu cartridge or on Ikeda 9 would be audio nirvana, with the SPU both sounded ok – but not extraordinary.

The SME 3009 and 3012 at their age today often have problems with their knife edge bearings – and, they are both not compatible with the G shell geometry of our SPU cartridges – so you have to deal with a compromise in adjusting the cart in a geometrically correct way.

The vintage Ortofon tonearms are one of the best possibilities, but you have to restore them, overhaul the bearings – also a new tonearm cable would be a good idea.

A great opportunity would be a Shindo tonearm, which is a variation of the old Ortofon tonearm, but these things are very, very rare.

The EMT 997 is also a good possibility, and they are available again brand new at Audiotorium 23 in Germany or Tone Imports in the USA.

Maybe the Thomas Schick tonearm, which you can buy brand new, has the best price to performance ratio of them all. This thing is an amazing opportunity to use an Ortofon SPU to its full potential.


Thomas offers a long version which is 12″ long, and a shorter version which has the size of 9.6″. The latter can be a direct replacement on most EMT turntables with their 9.6 EMT tonearms (which are not the wisdoms last conclusion to say the least….). A Schick tonearm and an Ortofon SPU is a match made in heaven – and if you now think, ok, some day I want to be able to change the cartridge – do I need another arm then??? I can reassure you – a Schick tonearm will also sound amazing with a Lyra cart, a DL 103, a Benz Micro and whatever you like, it is one of the most versatile tonearms on the market and one of the very rare “best buys” in the audio business.

I went into a slightly different direction, which has something to do with my turntable, which does not accept a 12″ armlength (Grrrrrrr!!!!). One day I contacted Frank Schröder, the famous German tonearm designer – because he uses different woods achieving different effective masses on his famous tonearms. Frank doesn´t use different kinds of wood, because they might sound different, as it will be the case with the construction of wooden instruments – far away from that. Frank uses a lot of different tinctures, oil and God knows what, to get rid of any sound variation of the different wood types. In the end you choose one specific sort of wood, because you want a specific effective mass at a given armlength.

So my approach was to get around 22g eff mass with a 9,5″ tonearm – something you cannot buy off the shelf. Frank listened carefully to my wish list, made some notes on a piece of paper and told me I have to wait nearly a year, because he had so many orders….. One year – that is hard stuff – but I knew in this moment that it will be well worth the wait, because this arm would be my second Frank Schröder designed – so I had a good idea what kind of outstanding performance was at stake!


Finally after 8 months (faster than promised!!!) I got my brand new Schröder DPS tonearm made out of snakewood, which is one of the  hardest woods on planet earth. The arm has 22g eff mass with an aluminium headshell plate and can reach 27g with a plate made out of brass – Bingo!!!! – that was my SPU tonearm.

And to tell you the truth – it is not used only for the classical Danish cartridge, I use it also together with a Miyajima Zero mono cart (in my book THE mono cartridge at the moment – but that´s another story), an Ikeda 9, and also with different Koetsu moving coil carts.

The Step Up Transformer


Next thing in our SPU requirement list is the amplification of this classic cart…..this old lady wants to see a step up transformer performing at its best. Such a transformer should have a turn ratio of 30:1 or even 40:1, depending on the achievable gain level of your moving magnet phono stage.

The Ortofon SPU Classic has an electrical output of just 0.2mV and an internal resistance of 2.5 – 3 Ohms depending which classic SPU you own. That is a tough task for nearly every phono stage – 0.2mV is half of what you get with a Koetsu Rosewood – so the decision to use a step up device is not a bad idea, if you want to have a jet black background while listening to your favourite records. But things are not as easy at it seems – because the higher the turn ratio of a step up device (more gain), the more degradation we can expect soundwise – so it is much more complicated and expensive to make a fantastic sounding 30:1 step up transformer, than to build one with a 10:1 turn ratio….

Finding a proper Step Up Transformer


There are some very, very good candidates on the market – mostly relatively unknown, because such devices are not made anymore by the large, well known audio companies. But there is a small hardcore scene, which delivers outstanding products.

What do we have??

Here are my top five:

1. The Hasimoto HMX and HM7 – both are 30:1 trannies and their sound is astonishing.

2. Auditorium 23 T1 step up transformer – there is no technical data available, but this step up device is specially made for the Ortofon SPU and sounds amazing.

3. Michael Ulbrich – these are huge trannies, bigger than CocaCola cans – but if you ask me, this is the best of the best at the moment! They look strange at first site – but the sound is audio nirvana! My number 1!

4. Mitch Cotter MK II L – an old classic, but a great step up transformer, you will get this unit only on the used market. It is not made anymore – and it is not a cheap affair – but really great!

5. Kondo Audio Note Japan S6 and also KSL – both are extremely expensive, the S6 is only available on the used market, the KSL could be bought new, even though there is a newer model coming up – some High End dealers will have the old KSL still in their shops. But take a deep breath – these units are ultra expensive – and they are good – but in my book way too expensive – Michael Ulbrich can do it much better for far, far less!

The cable between the step up transformer and your phono stage


The last difficult chapter is the cabling. If we use a step up transformer the cable between this unit and our MM (moving magnet) phonostage input is as important as the tonearm cable itself – both are the most important cables in the whole audio chain!

What the heck is so special about theses connections? The tonearm cable distributes the tiny voltage our SPU is able to deliver – that is 0.2mV – which means milli Volts – and milli means millionth Volts!!!!! This cable is connected to the input of our step up device – this unit is completely passive – so no power cable or power supply is necessary. To put it simple – our step up device is changing current into Volt – with a given turn ratio. The cable that distributes this signal to our phono stage has to be a cable with an extremely low capacity. Because the given capacity increases exponentially depending on our turn ratio! So you have to get the lowest capacity in a fully shielded cable you can get.

One of the best possibilities off the shelf is the Lyra Phono Pipe – maybe there are also DIY solutions I am not aware of – but the Phono Pipe is a very, very good cable for that purpose. It is perfectly shielded – which is important, because the signal coming out of our step up transformer is not a line signal – it is a high Z signal, which is prone to picking up noise, hum and EMI. The Phono Pipe has the lowest capacity at the moment of all cables I am aware of on the market, and it is beautifully made – and of course it is anything but cheap. But the sound and the ability to solve so many problems regarding that specific connection between step up device and phono stage makes it a very good solution.

What we get



The SPU mounted in the headshell of a top flight heavy arm, amplified with a very good step up transformer driving a tubed MM phono stage can deliver a sound you will never forget. The bass ist tight and full bodied – it doesn´t reach down to the absolut deepest regions, but what the cartridge delivers in this frequency band is the DEFINITION of punch!

The midband is warm, natural and beautiful – there is nothing distracting in it, no harshness, no glare, no roughness, it is a smooth, almost uncoloured midband. The treble is very special – it sounds wet as well as light and sweet. It is not the last word in resolution, but it has enough of it, if the music calls for it. The treble is never fatiguing – a SPU has the ability to project the treble in a three dimensional way – it is not just a sort of white noise we will detect on a lot of other cartridges, even in price regions in which normal people would buy a small car. This treble has gestalt and flow and a very high ability to follow even the biggest dynamic swings.
The dynamic abilities of a SPU are also very special – this thing can start and stop with a tremendous speed – it is anything but a slow performer, if the tonearm has the correct effective mass. The projection of space is one of its strongest sides. If you have never listened to an Ortofon SPU tracking some well recorded classical music – then you are in for a big surprise. These cartridges have the ability to show the stage in a manner I would call cinemascope style! In that very wide stage the SPU is able to render, you will have a slightly up front picture of the monophonic center stage. A vocal will come out of your speakers and is placed a good margin in front of the speaker base! A SPU is able to be big and bold, just as it can be intimate and fragile at the same time – that is something very, very special!

In the end it will give you the music as a whole experience, it is this holism, which makes it a perfect cartridge to discover music. It is all about the composition, the emotion and the feeling – not so much about every single detail and nuance a recording will show. It is also not a technical sounding cartridge – it shows music in its whole beauty – even if the tracks are not so well recorded or mixed and mastered – it is the perfect tool for a music lover!

Many variations on one theme



If you look at the Ortofon webpage, you will be surprised how many different SPU cartridges are on offer… will be too much for this article to describe every single SPU cartridge (in depth discussion of that will follow) – so I have to choose my favourites…

First of all – if you don´t have a tonearm with a SME bayonet connector to use the traditional G shell cartridges, you have to choose the 1/4″ mounting version, which is called Ortofon SPU N.

As I am using a Frank Schröder tonearm, it is not possible for me to use the G shell SPU cartridges – so I am limited to the N style SPU carts. Many SPU hardcore freaks claim that the N style SPUs are not real SPUs because the shell is missing – and I will tell you that is true – and a good thing – because the naked SPU doesn´t have the shell in which it resonates. If you don´t mind – call the N style carts more neutral.

If you are a novice my advice would be: buy the cheapest and most original one, the Classic SPU with a conical needle. In 2018, this is the closest thing to the original cart from the 50ties you can get – and it is maybe the best entry into the SPU-game!

If you want to have a little bit better tracking quality and some more resolution, then you pick up the Classic SPU with an elliptical stylus – it has a slightly modernised sound but dosn´t miss the traditional tone of these legends. A true classic with some upgrades in different sound categories – but it is as close to the classic sound as it can be.

The SPU Royal N or Royal GME (with the G shell) is something different – it is also a SPU but with a more modern sound character – the differences are the coils, the mass of the needle tip, and the stylus shape. Here, Ortofon uses a line contact derivate which they call Replicant 100. This SPU is a perfect starting point if you want to have a great portion of the classic SPU tone, garnished with some modern sound reproduction aspects – one of them is a much better resolution as the Classic SPUs will have. It is also the quietest SPU you will get regarding vinyl surface noise.

And last but not least, my personal favourite SPU – the Meister Silver….in the 1.5 Ohm version! This cartridge is placed soundwise between the Classic SPU with an elliptical stylus and the Royal N – it is not modernised as much as the Royal N – but it has more resolution than both Classic SPUs. It has maybe the best integration of the classic SPU tone with some very distinctive implemented modern aspects – a dream to listen to!

No matter what you choose – you will hear a high portion of realism in yor music, which is presented tremendously un-technically, fluid and emotionally touching – one of the all time classics.

If you are more a music lover and not so much an audiophile, then this cartride is for you!

Stay tuned.


E. Strauss



Turn on the radio, Marantz 20B FM Tuner


Sitting in front of a great tuner late in the evening, when all the daily trouble is gone and listening to some of the very good broadcasters here in Berlin, like Deutschlandradio and Deutschlandradio Kultur or Radio 1 is something very special.

Those broadcasters are not private stations, they are financed by a sort of tax, we listeners have to pay here in Germany (Rundfunkgebühren) – so they are not overblown with advertisement programs and could search their content which they bring on air more freely.

That means that you are able to listen after 8 O clock pm. on Deutschlandradio some live concerts they recorded themselves with their own very, very fine recording equipment, and you will listen to music never sold on a media like cd or vinyl. You get access to artists, who are not widely known or just the opposite – well known super star conductors and their orchestras, which play for you some music seldom heard. Sometimes they broadcast jazz festivals live or they invite the artists into their studios and record them live which results in very intimate music – in short – you have the chance to listen to very, very good special interest program.

Getting an FM Tuner


The only chance to listen to such program in proper quality, is to use a very good FM tuner. As you might guess, I am not a big fan of internet radio – and I hate commercial radio which broadcasts such an extremely processed sound, that there is less than 4db dynamic range left at the end. Very good radio in Germany means dealing with the small stations and mostly no private broadcasters.

Germany has a very narrow FM bandwith were all the different stations are located on – so a proper FM tuner must have the ability of a high station separation, to get rid of all that noise of little birdies singing behind the broadcasted program. A lot of separation means very steep filter design – and steep filter design often generates a sharp synthetic sound – so a good tuner is not something you will find around the corner.

Tubes or transistors?


Vintage tube tuners have an amazing warm and detailed sound, but most of them were made in the USA, which do not have the same bandwith – situation we face here in Germany, so the ability to get a strong reception and good separation is a task most of the vintage tube tuners could not achieve. And, if you think about one of the most popular vintage tube tuners – in may opinion the pinnacle of tube tuner design – the Marantz 10B, you need 22 tubes , most of them very, very rare. So a tube tuner is a nice thing to have – but if you judge the complete package it is mostly the second best way to achieve a fine radio tone into your listening room. On the other hand we have the modern synthsizer tuners, some late models with digital converters on board to feed digital amplification systems – these generation of tuners lack the classic, warm radio tone. This kind of presentation, the quality how radio should sound, was formed in my childhood. My dad drove an old Mercedes/8 – and in that car there was a radio installed – a Becker Mexico – which fed a huge oval fullrange speaker mounted on top of the dashboard. This radio sound was intoxicating! Voices sounded warm and deep with all that colourful proximity effect realised via a close up microphone position – music sounded big and bolt with a special wet treble sound – it was amazing. The other event, which formed my view how radio should sound was the purchase of an old Loewe Opta mono tube radio, I found one day at a shop dealing with vintage electronics.

How can I get exactly that tone with the ability to get a little bit more detail in the sound, more resolution – but without a synthetic attitude so often detectable with modern radio sound??

The Marantz 20B

L9991093 (1)

I had to get one of the famous first generation transistor tuners from Mcintosh or Marantz. And I opted for the successor of the famous Marantz 10b, the Model 20.

The Model 20 was made right after the 10b, which nearly ruined the Marantz company, because they made it in such an expensive way, that with every single unit they sold , the company made no revenue – instead they had to spent money.

As the famous Marantz 10b, also the Model 20 was constructed by Sid Smith and Richard Sequerra – both legends in the history of high end audio!

There are two variations of the Model 20 in existence – the Model 20 and the Model 20b, the latter is much more scarce that the Model 20. The difference between both is a modificated front end on the Model 20b and a slightly better output stage!

To find such a 20b is like winning the lottery – most of the examples you will see, are not working anymore – or they are “upgraded” with “nice” things like LED lamps or the circuits were modified. If you want to hunt such a rare piece of audio history, you need time and patience, and not indulging in illusion – these things have to be overhauled and restored to their original specs – you can do that by your own, if you have enough skills in working with some solder iron and in reading circuit diagrams – or you have to find someone who will do that for you. My example I eventually found,  was in a very poor state as I bought it – the front plate was bent, not a single lamp was working anymore, the stereo lamp circuit was defect, corrosion had done its work on the chassis and some internal parts, a couple of cpacitors were leaking….you get the picture. But it was love at first sight!

Restoring the blue eyed lady

I had to bring this thing to its specs and back to a much more beautiful condition as it was, when we first met each other.


I needed 6 months of research were to get the parts, getting the circuit diagrams, service manuals and a lot of soldering work. I tried in most cases to repair the unit with its original parts, which is not an easy task, because most of the so called NOS (New Old Stock) Parts of that time might be as much out of their specs as those found in the unit itself. But after 6 months there was a sign of hope – one evening I heard the first sound coming out of that classic tuner. Maybe you can imagine how I felt, as I listened to the first transmitter noise coming out of that old Marantz FM tuner – it was like me, the little Dr Frankenstein made his a dead believed monster to breath again. I am a happy man – because my wife (the most understanding girl in the world!!!) had to face weeks of a half occupied kitchen table with soldering iron, solder, small and large parts and an mazing amount of dirt on it – and she did not  protest nor was she annoyed.

Later I got in contact of an expert who was able to do the alignment of the tuner because I have not the special equipment needed for that job nor do I have any experience with such things. After the alignment was done, there was the first contact with our house antenna and the stereo system!

The tone is back


There it was!!!!

This specific classic warm radio tone, which left its mark on me since my childhood, the old Becker Mexico installed in my dad´s Mercedes / 8 which I never could forget during all that years – a sound I adored so much!

The Marantz 20b has an amazing quality in its low end – it is one of the most satisfying tuners in this regard – bass impulses broadcasted not with too much compression are nearly as full bodied as I can reach that with my turntable. The sheer impact is amazing, and till today, I found no other FM tuner capable to produce this quality of bass. The treble is completely open and detailed – not the typical rolled off sound so many FM tuners share – there is a sort of presence and light at the treble region, which is fantastic. Keeping in mind, that broadcasted program is cut at 15Khz, the treble performance made me to doubt for that fact.

In the midband the tuner has this classic warm and realistic touch, I do miss so much with more modern equipment. The whole gestalt of the sound is bold with the ability to create a huge soundstage garnished with a sparkling treble wich is smooth as silk. If you like the sound of vinyl, than this old Marantz FM tuner is not so far away from that aesthetic direction.

My biggest problem was to find the lamps, which Marantz used at this time – 6V/5Watt. You get everything in the 6V category, but not 5 watt…..this type of bajonet socket lamps vanished from the market.

One day I found a shop which sells parts for vintage motorcycles – and BINGO – this ebay shop had exactly what the doctor ordered – and my Marantz 20b struck again its sexy blue eyes.

Last things I had to do was dealing with the poor cosmetics of the device. The front plate has do be fixed, which needs a lot of gentle violence – but I succeeded. One of the biggest problems was the rusty original laquer at the steel chassis. A full repaint would mean to loose all the original stickers which were used on this piece of gear instead of some engravings. I decided to use a very tricky coating technique to obtain all the glued on signs once the Marantz factory had put on that tuner.


At the end the tuner got a new rope driving the needle which shows you the FM frequency, a new Telefunken oscilloscope tube and a complete cleaning.


To give you a short description of the operation, let me explain the features of that old audio classic.

The Marantz 20b has 2 pairs of adjustable RCA output sockets at its rear side. Beneath those you will find two spindle potentiometers to adjust the output level, as also the output balance of both pairs – their maximum output level will be 1V. Also at the rear side you will find two RCA input sockets, which lets you feed a signal into the tuner to have the possibility to use its scope, measuring that given signal. This comes on handy, if you adjust the azimuth of your phono cartridge for example. To activate any external signal fed to the scope, you have to turn the diyplay switch to its “ext.”(external) position.

Also at the rear side there is a pair of sockets for test purposes and we will find a strange locking pedestal which takes the 3 antenna inputs as also a switch on its backside wich adjust signal damping on the antenna signal. Last but not least we will find at the back a fixed power cable, my unit was officially imported to Germany, which means it is a 220V unit with a proper Schuko plug at the end of the umbilical. The European distributer for Marantz gear at this time was the Swiss company Bolex, who also built some of the most famous film cameras of that day (Bolex 8mm or 16mm cameras).

At the front we face on the left side two small potentiometers which are used to center the focus of the oscilloscope tube. If the tube is cold, after you switched the unit on, the scope will not match with the engraved cross marking at the screen – so you are able to correct that at the beginning of any adjustments done with the other switches or the tuning wheel – because the scope shows you everything you have to know regarding signal strength and multipath performance. So it is a good idea to begin with adjusting the scope. To do that you need to switch the knob called “display” to the point were it hits the “ext” marking (external). The scope shows now a small point, which has to be centered with the two potentiometers on the horizontal plane as also at the vertical plane – both are lettered accordingly.


The display switch has 4 more positions. “Audio” will show you the phase relationship between the two channels of your program on the scope. If you listen to a true mono signal, as it will be the case with speech, there is a 30° stroke displayed. If you have a strong stereo modulation the scope will show you more or less a circle with a lot of movement accordingly to the modulation of the music.

The next mode is off – that is self explaining – but I need to ad – off is a very good mode ;-))), because if you are not dialing in a station or observe the phase relationship between both stereo channels – it is a good idea to switch the scope off – because the tube will live much, much longer and to get a new one gets more and more complicated today.

The next two modi of the display switch, show you the signal strength on the scope or the multipath performance!

Next to the display switch we will find the knob for the different muting modes. The Marantz 20b has an adjustable (internal) muting threshold at which the signal will drop in volume, which is a nice feature, if you want to get rid of all that noise between two stations. But you can turn of that mode – and for that purpose exists the bespoke muting switch.

On the right hand side we will find the on and off switch and a knob  labeled with “mode”. Here you can decide if you want to listen in stereo or mono – but there is more…. If you listen to a weak stereo station, the noise you will receive is annoying – so there is a position between stereo and mono called “high blend”. Sid Smith used therefor a special trick in his circuit – it is a high frequency blend which uses phase cancelation of the noise – not a traditional high frequency cut. With that “filter” you will miss on weak stereo stations no treble! – That was a sensation at the time were the Marantz 20b hit the market. What you will loose is some spaciousness, the signal gets more into the mono direction – but is still a stereo signal!

All in all such a fantastic vintage FM tuner is a nice addition to a very good vinyl playback system – and at night, when I am listening to some rare music performance broadcasted in high quality, the wish comes up to record all that great stuff – but that is another story for another day.

My biggest respect goes to Richard Sequerra and Sid Smith, the inventors of the Marantz 20B, may Sid rest in peace, as he died in the year 2000…

Thank you for the music, you two genies….


E. Strauss


A miracle – Kiseki Purpleheart NS

My story

Those of us audiophiles grown up in the 80ties (last century) may remember: It was the time, were the Stereophile as also the Absolute Sounds magazine were like the bible for us, the time, were Nastasja Kinski showed her amazing curves on the front cover of the French erotic magazine “LUI” and we dreamt about Nastasja and a proper HiFi – system – but could only afford a Sony Walkman to listen to some 80ties stuff like The Cure, Joy Division and Prince or Michael Jackson (I was not a Madonna fan at this time….;-)))

One day my Sony Walkman headphones broke – a catastrophe, but a good occasion to visit one of the high end dealers in our town, instead of pressing my nose against the store window, I had now a proper reason to step into the shop .

So I pulled myself together and entered the shop…..oh my….. Micro Seiki turntables, Fidelity Research FR64S and 66S tonearms, Mark Levinson amps and preamps, a Cello Audio Platte and a Kiseki Purpleheart cartridge, mounted on a SME V tonearm. This little jewel got my attention – a dream, made of brass and a strange purple coloured wood with a tiny needle under its long body – it was so beautiful, that I could not forget about it in all the years followed that day. I promised myself – one day such a Kiseki will be mine – not knowing if it sounds good nor what such a jewel will cost. The following decade was stuffed with Rega decks and tonearms, cheap moving magnet carts, Mission amplifiers and tiny British bookshelf speakers – but deep inside my heart was still a purple shine from that Kiseki cartridge.


As the financial situation once changed and I eventually could afford such a cartridge, the company had disappeared – CD – players were now the holy cow, and Herbert von Karajan claimed – against the sound of the CD a vinyl record seems to be like gas light – how wrong he was!

Ok – no Kiseki for me – sometimes I saw some vintage ones on ebay or other audio selling platforms – Kiseki Agate Ruby, Kiseki Blue Goldspot and Kiseki Lapislazuli – but never was there a Purpleheart on offer.

Here and now


In 2010 I spotted some new old stock Kiseki Blue – and recognized that Kiseki was again back on track – the man behind that brand, Herman van den Dungen, coming from the Netherlands, decided to participate at the upcoming vinyl revival and used old parts from the 80ties to built a brand new Kiseki Blue. Since I was totally aware of that new situation – the complete series of these NOS (New Old Stock) Kiseki Blue were already sold out….

OK, again – no KIseki for me….

Van den Dungen realized that there was a growing market for his Kiseki cartridges and did a very bold step – he recreated the brand, now with new parts, a new design – and he called these cartrdges NS – which stands for new style.

Exploring the miracle


One day I found a little package at my doorstep – and my pulse began to rise. Inside the package I found the traditional round wooden box with the myterious Japanese writing on its top. Van den Dungen created the Purpleheart NS (New Style) in a different way he did with the Blue NS cartridges – the new style Kiseki Purpleheart had its traditional long body and looked like the vintage original which I was fascinated about since the middle of the 80ties. Oh, what a gorgeous looking pice of audio gear it was….nothing of its beauty had vanished in all those years – it was like I had a time machine, and was again in 1984 together with my old Walkman, the LUI magazine with Nasti on its front and all the great audio gear of that time – the only sign which tells me something was different, was the colour of my hair!

The new style Kiseki Purpleheart is a moving coil cartridge with an internal resistance of 42 Ohms, which means, that I could use it with a Denon DL 103 compatible step up transformer. The electrical output is a healthy 0,48mV – so a mach with a 1:10 Step Up transformer will give us clearly more gain, than with the classic DL 103 used with the same step up transformer. The cartridge has at todays standards an unusual long body made of the beautiful purpleheart wood. With some headshells or tonearms there might be a problem with space, as I intendet to use a Frank Schröder Reference tonearm, there was no problem with the size of the cart.

Mounting and adjustment


But there was a serious problem with the weight of that audio jewellery – the cartridge might look big and heavy but it is not – its weight is just 7g – to bring that into some perspective – a Lyra Kleos weights 8.8g and looks much lighter and smaller. There was no chance to get the optimal tracking force of 2.3g for that cart with the standard counterweight of the Schröder Reference – so I had to call Frank, praying, that he was in town and would have time to make me a smaller and lighter counterweight for my Reference arm. To my surprise Frank was at home, and offered me to come over the next day to pick up my lighter counterweight. Thank you Frank!!!!

Adjustment of the cartridge is not an easy task because you cannot see the tip of the stylus without making some Yoga exercise in front of your turntable. At the end I could have used the straight angles from the body, because the stylus of my Purpleheart was mounted with 100% precision – so no correction in geometry nor azimuth was necessary.

To get the most out of this cartridge I would advice you to use 2.3g VTF, which is a tad under the official figure – and a straight VTA, so that the top plane of the cart is parallel to the record surface. You could use a full active phono stage with up to 1 Kohm internal termination, but I think the best sound will be achieved with 400 Ohm. Or you can use  a step up transformer in the range of 1:10 or 1:15 – i opted for the latter – and connected the Purpleheart with the Hashimoto HMX trannies in my Air Tight ATH2A using its high impedance switch. The transformer will give us 23db of gain, and the cartridge “sees” around 210 Ohm.

The sound

The first thing I recognised was the silent ride of that cartridge – you wont get much noise from the grooves, which means, that we have a larger dynamic window for all the small details. The Purpleheart needs less than 20 hours of playing time to come to live – that is something I cannot stress enough – because today some cartridge manufacturers tell us – you need 150 – 300(!!) hours to judge the sound of a moving coil – which is ridiculous. What we can expect after round about 20 hours is a bit more openess in the treble region and a more fluid sound in the midband – but it is not a dramatic change.

Kiseki means miracle – and the name could not be better chosen – because the sound is like a miracle. Out of a very black background we get a fast and articulate sound, with bold colours and a silky smooth top end with an amazing amount of detail and resolution. The bass section is sinewy and reaches into the deepest octave – this bass performance is fast, and has a lot of tone – not that typical one note deep bass with slow action. The stage the Kiseki is able to render has a slight up front gestalt – a singer is not on level with the speaker plane – instead he is placed a good portion in front of the speakers, which gives us a very intimate vocal performance. From the mono center toward the sides, we get a very good rendering of recorded space with a lot of detail and an amazing resolution. The space between the instruments is also very good – not on par with a Lyra Kleos SL – but there is not much missing. The kind of projection is a mixture of pin point accuracy and a sort of wholeness, which makes it very easy to get the whole picture of a recording, while also being able to listen to a large amount of detail.

In comparison with the Lyra Kleos

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As the price of the Kiseki here in Germany is around €3000,- it is fair to compare it with one of the best cartridges in this price range, the Lyra Kleos SL. Both perform in a wide margin above its price class, you have to spend nearly €2000,- more to get really something more. And this “something” is not another class or a whole different picture – differences are shown in the amount of resolution and attack pureness, as well as the blackest black in bass of the really big boys. As you spent such a serious amount of money for a moving coil cartridge, it gets difficult to gain more sound quality for the developer of those high end gems. So do not expect a complete different sound quality if you spent €6000,- or more – as I said – you will gain performance in some single aspects of the reproduced sound. A Lyra Etna for example puts a better resolution on the table and has a tighter and deeper bass register with a good more portion of dynamic shades, than a Kleos SL can give us. What I try to explain is – from a certain price range on, you have not a linear function between your investment and a better sound quality. There are some “jumps” in that function between price and sound quality which take place from under €1000 – to the limit of €1000, and there is another bigger gap existent if you double your investment to around €2000,-. After the 2000,- mark it gets much more complicated – so the next little jumb will take place at €4000,- but it is much smaller, than everything till that point.


The Kleos offered in my comparison a better pronounced leading edge. The Kleos has the ability to start and stop immediatly. The speed of this cartridge is astonishing – the Purpleheart in comparison is a little bit slower with not so much accent on the rhythm of the music. The story behind the Kiseki is more about the tone – and in this category it is more beautiful than the Kleos. The latter might be more neutral more transparent, but the Kiseki gives you a more emotional picture of the music. There is a certain emphasis on the lower midband, which renders the body of instruments and vocals with greater impact and a greater sense of authenticity. Both share a nearly equal ability to render recorded space, the Kleos is doing that in a more pin point kind of way, the Purpleheart shows us the soundstage in a broader more bolt style, which makes it sounding a little bit bigger and greater. In the treble area the Kleos is more refined and more open with a greater sense of resolution and detail, the Kiseki is a little bit on the warm side of neutral at this point, which can be an advantage if the engineer or the mastering facility cut the treble slightly too hot, which is often noticeably with the sibilance S or T or SCH. On the other hand the Kiseki is not rolled off – it renders the highest treble with a slight drop of energy – and while doing this, there is a very sophisticated quality at the treble – it sounds wett and three dimensional.

The Kleos is a bit dryer in that area and misses some of the plasticity of the Kiseki. The Midband of the Purpleheart is one of the best I ever heard – it is so colourful and real, with a huge dimension – a dream! The Kleos is fleshed out with an ever so slight cut in the upper midtone spectrum – which gives it the ability to render a very clean and structural sound, even if the record gets more dense and highly dynamic. Both are amazing cartridges – I would vote for the Kleos if you are a kind of listener, who is consuming music in a more intellectual way – the Kiseki touches more the heart and soul of the listener. And the Kleos is more about rhythm, while the Kiseki is more about tone – so both will be a perfect complement to each other.

There is a certain tendency to have more than one tonearm mounted on a record player…..

Relax and enjoy your music

E. Strauss

Introducing a Legend, Telefunken ECC83 Smooth Plates


If we think of music reproduction, 90% of the whole information in a piece of music, even more with spoken words, takes place in the audio midband. As we were young dance club visitors the most important thing in sound reproduction was bass – more bass equals better reproduction and greater fun – we had to feel the energy right in our chest. With getting a little bit older, things changed and today I cannot stand 10min of reproduced sound, if something in the midband sounds wrong or coloured.

Where everything began


The best example of the human capability to hear the slightest variations in the midband of the audio spectrum is the voice. If we have our girlfriend on the phone, we can hear in less than 3 seconds in which emotional state she is, and we can also identify a known voice after seconds, even if we haven´t spoken to that person for years . In this example we are using a telephone not a high end audio system – just a simple telephone. The ability to remember the character of different voices we once heard and to recognize even the smallest nuances in them is frightening. If we think about the evolution of us human beings, the ability to listen at such a high level, has something to do with our existence on planet earth, and the sound of our mothers voice was  familiar to us a long time before we were born.

The Goal

Thinking about serious sound reproduction means to deal with the midband. And dealing with the midband is much more complicated than with bass or the treble. Do not misunderstand me – bass and treble are also complex in their own way – but the diversity of the midband, the amazing amount of different shades and the ability to detect them, makes us to real “midband gourmets”. To get more information about the hearing of the human ear, we have to look at the findings of Fletcher-Munson, who manifested in 1933 the famous curves, in which we will see how loudness levels and the ability of our ear to her different frequencies is described. If we take this curves as a fact, we have to get the highest quality in that frequency range in our sound reproduction system we can afford – and – to tell you the truth – it is not cheap nor is it easy to achieve that.

The Midband


One ticket to heaven in the difficult midband area is a very good tube amplification system. That does not imply that transistor technology is not able to reach an outstanding quality in this regard, but to get there via a transistor driven amplifier or preamplifier will be even more expensive than with a tube amplifier.

But a tube amplifier needs tubes – and there the whole story begins to turn. Today we face a growing number of tube suppliers mostly located in russia and china, which give us the most common types of our so urgently needed glass – but how good is the sound of these brad new constructions? If I put brad new JJ or Electro Harmonix tubes in all 12AX7 positions in my preamplifier, the sound  gets more of that specific colour I will find in a cheap transistor preamplifier – sometimes even worse that that. Gone is the complexity of the midband, gone is its smoothness and the grain free gestalt, what I get is a sparkling treble and a nice sounding full bodied bass, but the midband is flat and lifeless, with a clear cut in that frequency range. In other words, if someone will steal all the great old tubes from my stach – I would by tomorrow a very nice and expensive transistor preamplifier – and get rid of all the tube procurement, all the tube rolling, the fine matching to the amplifier – and at the end I would probably save some money too. I cannot tell you, why it is not possible in 2018 with all the computer technology, the materials we have today and the indsutrial possibilities to make tubes with the same sound quality it was the standard in the 30ties, 40ties, 50ties and 60ties of the last century. Maybe computers and all the modern technology we have today are able to create the newest I phone – but are useless to built a tube like the Telefunken ECC83 – who knows.

Meeting a Legend


The Telefunken ECC83 is one of the most important tubes in its class – maybe the most important one. It was made in the Telefunken plant in Berlin – and has some distinctive marks which we have to talk about later. The Telefunken ECC83 is maybe the one and only tube in the ECC83/12AX7 range, which behaves is such a neutral way with its sound characteristic, that we are able to hear the quality of a given circuit. That makes this tube for some of us boring – you plug a Telefunken ECC83 into a line stage and the big miracle you will have with a Mullard, Amperex, or RCA Black Plates is seemingly missing. But that is just half of the whole story. A Telefunken ECC83 smooth plates has not the typical shining light to any frequency range or a special dynamic behaviour in the spectrum – nor has it any obvious coloration, but it has one of the most complex midband abilities of all ECC83/12AX7 tubes. You will get a highly neutral ultra complex tube sound, a sound, which needs your attention – it is not a sound were you can read a book, while listening to some music. A Telefunken ECC83 sucks you into the music – and it challanges you.

Together with its neutral full range sound, you will also get an outstanding quality in reproducing recorded space – the smooth Plates Telefunken will render the slightest amount of reflections once captured by the microphones. If you put the RCA Living Stereo with Haifetz´s Interpretation of Sibelius Violin Concerto D minor Op.47 on the platter of your turntable, than you will recoginze after the first movement – it´s all about tone. Hot and cold shivers coming over you while listening to this violin tone – reproduced with a Telefunken ECC83 smooth plates it is so frightening real, that you nearly can touch the instrument. The ability to show the whole spectrum nearly uncoloured and especially the complex midband, makes this concert a very intense experience! The smooth plates Telefunken ECC83 is one of the biggest legends in the ECC83 class of tubes and it´s status there is completely justified!


A trip to the past

The Telefunken ECC83 was used in countless legendary amplifiers of the audio or recording industry, it helped a lot of companies to gain their specific sound, which we adore even today. To name just a view….what happens, if you throw out all 6 Telefunken ECC83 of a Marantz 7C preamplifier – what if you do that with a Mcintosh C22 or with a Telefunken V72 microphone preamp??? Marantz and Mcintosh are more or less the inventors of what we call today High End – and both companies used wherever it made sense at their 12AX7 positions Telefunken ECC83 tubes. The whole US hifi scene in those years used them, Fisher, Scott, Harman Kardon and so on….sometimes they got from Telefunken tubes with their brandname printed on the glass – so it might be possible, that you have seen Telefunken tubes with Fisher and Rogers as also Mcintosh logos on their glass. As Germany was forbidden directly after the second world war to build any arms, the recovered German tube industry concentrated on civil usage of vacuum tubes and one of those fields was the reproduction of sound. Maybe that´s the miracles behind the sound of a Telefunken ECC83. Telefunken had not to deal with constructive details imperative,  if their tubes were used in supersonic jet fighters or bombers which can fly at the border of the stratosphere. Strangely enough, the Telefunken is inspite of their civil purpose, a very rugged construction.


What about noise?

The smooth Plates are one of the very rare tubes which have nearly no problems with noise, nor have tey any tendency to get microphonic. Both attributes make them predestined for the use in very sensitive applications, as we will find them in phono and pre amplification stages of our sound reproduction systems. Imagine a phono stage constructed with two gain stages which will amplify the signal up to 40db – every bit of microphonic behaviour of a tube will cause an earthshaking noise coming out of your speakers. Once you reached a certain quality level of vinyl reproduction – it is the signal to noise ratio, which divides the boys from the man. As blacker the background will be, as much details and recorded space you will get – any tube hiss will weaken the ability to show the dimension in space of the recording. In a phono stage a tube can´t be quiet enough – and with the Telefunken ECC83 smooth Plates we can achieve a level of quietness no one would think is possible using a vacuum tube.

How to spot the original


There are 5 different versions of the Telefunken ECC83 in existence – the oldest ones are called ribbed plates. The anode plates of this tubes have on their flat sides a certain pattern, which could be described as a ladder – or ribs – which gave them their name.

The smooth plates share 4 different variations – all of them differ in the numbers and positions of the holes at the side of the plates – and of course the smooth plates misses the ladder structure on their anode plates – which made them – the smooth plates!

Type 1 of the smooth plates have two rectangular holes symmetrical arranged on top and bottom auf their plates structure.

Type 2 has 4 rectangular holes at the side of their plate structure.

Type 3 has 3 rectangular holes on the side of the plate structure.

Type 4 has again 2 rectangular holes in the plate structure – but this time the holes are more centered – not as far away from each other as it is the case with type 1.

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All original Telefunken small signal tubes have the diamond logo at the  bottom of the glass  between the contact pins – that is more important as we might think – because at the end of the tube era Telefunken stopped making their own tubes and sold re labeled tubes from the east german supplier RFT. Those RFT – “Telefunken” banded Tubes do not have the diamond logo between their pis. The great thing is – no one can fake this sign in the bottom of the tube – because it is a structure casted in the glass.

All Telefunken ECC83 have a code on the opposite side of their logo, which begins always with a capital B – which stands for the plant in Berlin/Germany. Telefunken had also a plant in Ulm/Germany, were they made all the power tubes and their special high grade signal tubes(Telefunken “S class”) – in such a case there will be a capital U at the beginning of the code.

The Logo itself changed over the years – very old ribbed plates Telefunken had a small diamond shaped Telefunken logo printed on the glass – later dated smooth plates have the more common large and thinner printed logo.

On the left and right side at the bottom of the logo you will find the writing “Made In”…………”Germany”. At the bottom of the tube you will find the type – in this case ECC83. If the tube was made for export purposes, there will be both type names – the international /US type 12AX7 and the European type name ECC83  separated through a slash.

Some Telefunken ECC83 have numbers, normally three digits, on their getter mirror on top of the tube – this was a special numbering of internal batch matching processes.

If the customer needed special selected tubes, as we will find them in medical or industrial applications, there might be a coloured tip – mostly in red or blue on top of the tube.

Some special grade Telefunken ECC83 have a bank wrapper around their glass with selection informations and names of the company for which they were made – like Tectronics for example.

And there were also Telefunken ECC83 tubes, which were made for the German Post and telegraphic applications – those have in addition to their normal logo a coloured code around the glas. I have such a pair with a red code index for telegraphic applications – but there might be also yellow codes or other coloured codes as well.

All Telefunken ECC83 are long plate types – Telefunken never changed that construction detail, as most of the other tube suppliers did at the beginning of 1960. They all have a round getter ring fixed with one getter support rod, and they should have, if they are in good shape, a shiny silver coloured getter flash. The glass on the getter dome changed over the years – the oldest smooth plates and ribbed plates have 4 segments on their dome – newer examples have a smooth glass dome.


In comparison

A lot of electro technical engineers deny that there will be a sound variation between different tube brands sharing the same category like in our case the ECC83 family. They claim,  that if two tubes share the same measurable data determined with a tube tester, and have the same internal resistance, than both tubes should sound equal.

As I am an audio engineer myself – I am far away from believing in Voodoo, but I must say that the sound differences between different tube brands in one given class are dramatic. A Mullard ECC83 long plates, square getter, wrinkeled glass (MC1) sounds completely different, than a Telefunken ECC83 smooth plates – soon we will discuss that more in depth.

In this case I wanted to know how a modern tube would perform in terms of sound quality against an old Telefunken ECC83. So I did some investigation at the internet to inform myself of the possibly best modern 12AX7 and got as many nominees as there are tubes on the market – but one specific tube stood out of the mass – that was the New Sensor made 12AX7 Gold Lion.

I bought a triplet of those, perfectly matched from a well known tube supplier in Germany and wanted to compare them with a equally good matched triplet of the legendary Telefunken ECC83 smooth plates type 1 with equal production codes.

As we all know, tube rolling is not a game were we can directly compare the sound of two different tubes – because we have to switch the amp of, we have to wait till the tubes cool down before we can pull them out and plug in a new set.

In the professional sound engineering  world, we claim, that our memory dealing with sound will be fooled after 30 seconds – so I decided such a comparison has to be done in a better way. I decided to record the music rendered by the two different tube settings, using a professional 24bit, 192Khz digital hard disc recording system.

After I finished recording of 4 different types of music using the exactly same records, the same cartridge, same turntable, same cabling – everything being as equal as possible, I used a normalize algorhythm  to bring both files at the exact same gain level to get rid of eventually existent gain differences – and listened for a couple of days to the recorded files via headphones and via my Quad ESL 57 and a pair of vintage Chartwell 1 LS3/5a. Later in the test procedere I made blind tests with both tube settings.

And what was the outcome???

In comparison to the Telefunken the most obvious impression you will get with the Gold Lion 12AX7 is a more pronounced bass – it seems to gs a little bit deeper and had a greater sense of dynamic, which gave the bass range a greater impact.

On the other side of the audio band you get the impression the Gold Lion has more sparkling treble with a pronounced roll off in the highest range of the frequencies. This character of the Gold Lion 12AX7 has its origin in a compressed midband – which makes the bass frequencies stand out – as also the treble spectrum. It is the typical – “hello – I am a great HiFi sound” tube character, which so many people fall for it.

With the treble character it is not so easy to describe the difference. An old audio engineer rule says, high frequencies mask lower frequencies – if you cut of the highest spectrum, you get a more pronounced presence in your sound. And that was exactly the case with the Gold Lion 12AX7 – the frequency range was comparable to some MP3 files, were you will not find much signal anymore above 15Khz  – but in spite of sounding dark – you will get the impression of more presence. The Telefunken had the complete spectrum – and this is the reason why a vocal does not jump on you – it is placed were it belongs. The Gold Lion made the presence of the treble more pronounced more sexy but it lacks a lot at the absolute top end of the audio spectrum. If you listen to a singer songwriter track it might be nice, but if your next music sample is some Jazz with pronounced cymbal work, you will recognize that something is missing. Also the compressed midband and the pronounced presenc could make the Gold Lion sounding harsh – because all the smoothness of a balanced tone is gone – what is left is an unbalanced sound which should impress you in the first instance. In the area of rendering recorded space the Telefunken could jump over the Gold Lion – it was no comparison – the New Sensor construction sounded flat and two dimensional. The Gold Lion was simpler – more easy to listen to, it draws less attention to the details, less space, less midband accuracy and a kind of loudness curve was detected. The dynamic abilities of both tubes were more than obvious – the Gold lion compressed the midband from 350hz – 1,5khz while the Telefunken sounded completely open in this range.You will get with a recorded violin the whole gestalt of the instrument – every nuance of it was there with the Telefunken ECC83 while the Gold Lion made it more simple, more easy listening.


Prices and supply

A Gold Lion 12AX7 costs us with a good matching process around 50,-, the Telefunken ECC83 will set you back around 80 – 100,- – so it is much more expensive. But – you payed a lot more money for your phono stage, your cartridge and your tonearm, as also the turntable itself – if you want to keep the signal chain as neutral and as open for what you feed in it, than there is no other way as to bite the bullet and get some good quality NOS tubes!

And do it now – because every year the things get more and more expensive – we are probably the last generation, who will be able to consume the fruits of a technology obviously forgotten in our modern times. We face much larger demand of NOS tubes than the market can deliver – a proved sign are raising prices. The same Telefunken ECC83 costs 8 years ago 50,- exactly what you have to pay today for a Gold Lion 12AX7 – and I thought that was really expensive in those years.

If you spent such an amount of money for a single tube, you should be certain to get good quality – so I am not a big fan of countless ebay auctions with no tube tester is involved or tube testing equipment is used, were you can not work with the data published at the auction.

Buy from trusted sources – pay a little bit more and forget the story of the dead grandfather with a stach full of brad new Telefunken without any sign of a label on the glass or dark getter mirrors. At the end such an expensive Telefunken ECC83 could be also the better decision in the long term, because such tubes will be durable around 10 000 hours – during that period of time it might be, that your third generation of Gold Lion tubes will be necessary.


Great listening

E. Strauss




Quad ESL57, for the closest approach to the original sound. Part 1


So much has been written about the classic Quad ESL 57, that it is worthless to repeat the historical aspects of this famous electrostatic loudspeaker or describe the technical aspects of its construction.

My intention is, to give some practical advice about room placement and how to match this speaker system with an amplifier. How to deal with its shortcomings and how to enjoy its outstanding performance.

Getting a pair of Quads in proper shape

The fist adventure with the original Quads is, to get a fully functional pair. If you are not willing to deal with restoring their panels and working with lethal high voltages inside its electronics, it is a good idea to skip the typical ebay auctions or cheap offerings of old used ones and contact one of the professional suppliers. In my case it was Manfred Stein from Quad Deutschland who got my attention, because the small German company bought all the original tooling from Quad UK as they were sold to Shenzhen China. Manfred Stein was a Quad Distributor during the heydays of the British company and shared a close relationship with Peter Walker, founder of Quad Electroacoutics Ltd, and father of the ESL 57 speakers. As Quad UK had to close their doors, Peter decided to sell Manfred Stein the whole machinery park, so that he is able today to restore the original Quad ESL 57 and its more modern brother the ESL 63 to its  original specifications.


So I voted for an old classic 57 with its typical bronze coloured front grilles, which was completely refurbished and brought to the original specs. Manfred Stein gave the speaker, manufactured at the end of the sixties last century, brand new panels and overhauled the complete electronics while letting the original transformers untouched. Most of what you can read on the internet about the efficiency of this old speaker design has to be seen in the context of its state at the moment of listening. Old, sometimes defective panels will not have the performance they once had, which causes the listener to pump up the volume on his amplifier, to compensate for the compromised efficiency. Such action will ruin the speakers even more, because the danger of overloading them with your amplifier rises, which will cause the well known arcing of the treble panels.


A historically correct refurbished ESL 57 will have an efficiency around 84db/1w/1m, which is in the same league as the famous BBC LS3/5a speaker system. That is everything but especially efficient if we look at horn loaded speaker designs or actual modern constructions, so the typical way to go is using a very, very strong amplifier – but it is not! The ESL 57 accept 33V at maximum on its terminals bevor arcing occurs on their treble panels. The amplifier designed for the ESL 57, the Quad II monoblocks, delivered 15 watt to drive the speakers in a safe way. So the ESL 57 will not accept a super strong amplifier which will limit the maximum SPL we could reach with this speakers to around 100db in 1m.

100db in 1meter is not too bad, we could easily listen to nearly every piece of classical music with a realistic dynamic swing, as we can do with Jazz, Singer Songwriter and also modern Pop music – the limit will be Heavy Metal or modern electronic music and also very large orchestral pieces like Mahlers second symphony. But I wrote 1 meter – 1 meter will be extreme close up listening – or better nearfield listening, which is not possible with the ESL 57, because of its poor sound radiation in any given room at this distance. The minimal distance we can achieve is around 2m measured from the treble panel to our ears. Every doubling of the distance, results in a 6db drop of sound pressure level – which means that nearfield/midfield listening with the Quad ESL 57 is a good idea to get enough realistic and dynamic expression in a not too large room.

The impedance

If we look at the 33v maximum Volts the ESL 57 will accept without being destroyed, we haven´t yet discussed the impedance curve this speaker produces on different frequencies. To make things much more complicated, the Quad ESL 57 is a very reactive load for our amplifier, the panels will produce an impedance peak around 100hz – of nearly 40 Ohms – and in the treble around 17Khz we see a serious drop in the impedance curve of under 2 Ohms. That is not an easy load for our amplifiers. To match the original ESL to an amplifier is a task which books were written about. To shorten the story at this point (later on we will discuss this more in depth) – my advice is to use a very good push pull tube amplifier with high class output transformers or an OTL (Output Transformer Less) amplifier – both will work in a fantastic way with this little diva!



Nearfield listening and a dedicated room

Coming back to our nearfield listening approach we have to think about some more surprises the original ESL has in store for us. The 57 is a dipole speaker – this means it will radiate the sound pressure not only in front of its panels, we also have to face a distinctive radiation behind the panels. The radiation of the sound pressure has the characteristic of a figure of 8, which means there is total cancelation 90degree of the panels. The sound wave radiation at the rear side of the panels is damped with some felt and jute pieces – so we do not have a mirrored radiation in the front and at the back of the speaker. The truth is, that at the rear side we have a lot of damping at the higher frequencies, but nearly no damping in the bass region of the frequency spectrum. If we place the ESL close to a wall, the rear radiation of the speaker will be heavily compromised. With the construction of the ESL 57 we have exactly the opposite behaviour of an enclosed speaker system, which raises the bass frequencies by placement close to the rear wall or even worse by corner placement. With the dipole characteristic of the 57 we have a proper tool to adjust bass performance in any given room to get a linear response. That means as far as we could get the Quads from the rear wall, the more sound pressure level we will get at the low end of the spectrum. Everything depends on the room in which the speaker is installed – a good starting point is to place the panels at 1/3 of the rooms length. This position is nearly unachievable in a living room, if you still want to be with your girlfriend or wife. ;-)) A dedicated room is the best way to get rid of all limiting circumstances, wether it be furniture or just the pure design of the room. The big question is now – shall I put the panels on the long or the short side of a dedicated listening room???

Room placement

In the case of a pair of BBC LS3/5a I would strongly suggest to choose the long wall of the dedicated listening room (a topic I will write about in another article) – with the Quad it is just the opposite – if the short wall is not too short, which will harm the amazing ability of the Quads to show recorded space, we will gain sound pressure level and bass performance with this kind of placement.  Remember, we will listen to the stats in a nearfield placement – so you will need at least a minimum of 4m width of the short wall in your listening room – if that can be achieved, you have finished choosing the wall at which the ESL 57 will be placed.

The distance from the rear wall starts with a minimum of 1m – under this distance you will compromise the sound radiation in such a way, that all the moaning about bass performance in most of what is written on the internet will be justified. My room is 4.5m long – so if we use the “one third” rule, the speakers should be placed around 1,5m away from the rear wall, which is a good starting point. Quad experts will now shoot at me – because that is not enough – but wait – we are talking about a nearfield listening situation – and we are not finished with the placement.

The next step is to adjust the distance to the side walls – as we chose the small wall of the room, we will not have too many possibilities – because the room is not wide enough to get the panels far from the side walls AND achieve a proper stereo base for them. But there is a reason why we chose the smaller wall in our room – and the reason is again the bass performance and the efficiency. If we place the Quad ESL 57 near to the side walls, we will get more bass level from them and more sound pressure level – so we have two screws to adjust bass with the placement of the speakers, distance to the rear wall, and distance to the side walls. But there is no profit without loss – if we would place the ESL 57 nearly in free space – far away from any wall at the sides and behind them, we will have an amazing spacious sound but serious restrictions in bass and sound pressure performance.

On the short wall of our room, with around 30 – 40cm distance to the side walls, and 1,5 – 1,8m distance to the rear wall, we can measure a maximum sound pressure level at our sweet spot nearly 2m in front of the ESL 57 at the maximum 33V coming from our amplifier of nearly 100db spl, and no drop in the bass frequencies up to 42hz. The side walls of our room act like an acoustic amplification system!

As we discussed earlier the panels have no sound radiation 90° of the axis – so at this stage there will be no reflection from the side walls of our room – but the speaker will get an angle in which it will be placed towards us, which changes this situation. This means there must be a certain distance from the side walls if we want to have a breathing speaker and no boomy bass response! It is also a good idea to give the space behind the speakers and the side walls near the panels some acoustic treatment, to avoid too much early reflections.


Toeing in

If we put on some music without any toeing in, we will recognize that there will be very poor imaging and a serious drop in the treble performance – the sound will be really bad!!! To cure all these aspects, we have to give the panels a certain angle in which they radiate towards us. To get the perfect stereo triangle placement, we will place our chair at a point were our ears equal the distance between the center of the two treble panels – in my example it will be 190cm. The treble radiation of the ESLs is limited in the horizontal plane to about 30° measured symmetrically from the center of the treble panel axis – and even worse – 15° in the vertical plane. And there is another detail in the construction, which we have to know – the treble panel is not mounted at the same plane as the bass panels are – it sits behind the plane of the bass panels – which is a good thing regarding the time alignment of the whole construction, but you should keep this detail in mind, because at large angles this construction detail causes diffraction at frequencies above 3Khz!

We have to toe in the speakers in such a way, that the very directed high frequency sound pressure level has direct access to our ears – too much toe in, and the sound will become too unbalanced in the high midband and lower presence – the Quad ESL 57 will shout at us. Too little of an angle, and we will miss the highest treble and air. This adjustment will take a lot of time – a good help is to use a noise generator available on the internet, and listen to some white noise trough our speakers. Some of the white noise generators available have the possibility to shape the noise, so that we can drop lower frequencies and listen only to the highest frequency band – you will be amazed how directional the Quad will be in the highest treble range! Our aim is to get a perfect stereo triangle – so if we realise that we will get more treble energy by varying the distance towards the speakers, we have to work on the angle again. We are finished when we get the most treble energy at our listening point in the stereo triangle – it will be achieved at around 15° toeing in of the panels. And do not give up!!!!

At the end of these adjustments, you will crawl on the floor with a ruler in your hand and your ears will distinguish every single degree of angle variation. You´ve succeeded if you listen to a vocal with some natural reverb captured in the recording and the singer is right in front of you, perfectly placed in the center of the stereo image and the reverb vanishes smoothly and absolute symmetrically between the two speakers. Next listening test is a walking base figure played in Jazz music – get different tunes written in different keys and listen carefully to the bass – there should be no bass bump or drop at any tone the bass player performs. If that might be too difficult – get a sinus tone generator from the internet and put some frequency sweeps on the Quads – if there are bass bumps or cuts, you have to vary the distance to the rear wall and maybe also to the side walls. In the end we should achieve an even bass performance, while getting the most treble and spacious sound with pin point imaging from the Quads. If you take great care placing the stats in the room, these speakers are able to vanish completely as a sound source, while throwing a three dimensional sound at you with an amazing pin point accuracy. Do not give up, till you have reached the maximum – every little change has a great effect – it is not plug an play!!!

The height


A lot has been written about the original three feet floor placement of the ESL57 and about upgrading this with some higher stands, to bring the panels up to ear level.

The same people will tell you, that you need stacked Quads to gain sound pressure level and bass performance. Peter Walker had a reason to place the ESL 57 as he designed it – and one of his strongest arguments was the coupling of the bass panels to the floor. If we raise the panels we will get around 4db – 6db drop in the deep frequency spectrum. But raising the speakers from the floor also has a strong advantage – you get a very, very good stage and pinpoint performance and the soundstage will be much better, than sitting in a normal chair and listening to the panels on their standard feet. So how can we bring all these things together….??? The solution is adjusting OUR height instead of the height of the speakers. A normal chair is much too high – we must choose a chair or armchair, which brings us to the level of the ESL speakers. A narrow armchair or a chair like the Vitra LCW is as if it’s made for listening to our beloved Quads. Our goal is, to bring the ears below the top plane of the speakers – a sitting height of around 30cm will achieve that, without loosing the bass coupling Peter Walker once designed with his short legs under the panels. To gain a realistic stage, the panels have a slight angle backwards – if you listen to a singer, placed exactly in the center of the stage, you should “see” the voice straight in front of you without having the feeling of looking down to the stage. Now we´ve gained a realistic perspective to the virtual stage captured in our recordings….. and yes, a Magnepan is able to show us that stage in a way, that we have to raise our head – we look up to the stage. With the ESL 57 we look straight, sometimes a little bit down to the music. The difference could be described like this: with the Magnepans we are standing in the first row of a live concert and looking up to the singer on the stage, while with the Quad ESL we are sitting in the third row of an orchestra hall looking slightly down to the performance on the stage.

Why do we listen to the ESL, a design from 1957?


As we can see, there are seemingly a lot of disadvantages in using an ESL 57 speaker to enjoy our favourite music… why do we choose such an old construction?? Why were they used as a control monitor for (classical music) recording and mixing in a lot of studios around the world and broadcast environments, and why are they still used today by engineers like for example David Chesky of Chesky Records?

If we read the headline of this article, Quad claimed, that the ESL would be the closest approach to the original sound – and this is from my point of view not only some advertisement. Until today the Quad ESL 57 show 95 of 100 modern speakers what a realistic reproduction of the whole midband in the sound spectrum is. The stats are able to produce the human voice in a manner, that we can believe a human being stands in front of us and sings. The string tone of these speakers is so realistic and pure, without any coloration, that we learn a lot of new things about our records and recordings. Even the slightest “mistake” in a given recording or within our audio system is clearly detectable. The Quads act like an audio microscope without being analytical or dissecting. We can enjoy music as a whole experience and we can also zoom into the finest details, and this zooming can be done without the slightest feeling of getting tired or stressed while we are listening. If we place them as monitors in the nearfield and let them sit on their original feet, we get enough sound pressure level and also a bass performance that is more than enough. If we think like a mixing engineer, we must accept that the human ear reaches its maximum linearity around 86db in the sweet spot. If we sit 2 meters in front of the ESL 57, we gain a maximum sound pressure level with my special “nearfield” placement of around 100db at the maximum rate of 33V driving the panels – that is 14db above the average level in which our ear shows the highest degree of linearity. 6db means doubling the volume, so for the highest dynamic swings in our music we have around 14db left to describe the given dynamic. That works perfectly if the room is not too big – and if we are not fans of Metallica live on stage. The bass response reaches down to 40 – 45 hz if we have placed the stats with great care, which means that we can hear the deepest tone played by a traditional 4 string bass guitar or an upright bass. The quality of the bass is phenomenal – no coloration of any enclosure, no boominess, therefore we get a speed and articulation, a toanlity in the deepest octaves, which is so realistic, that it is a great pleasure to listen to music which is produced with good bass performance.

The soundstage which these little wonders are able to throw into our listening room is astonishing. The midband is as natural as breathing and the immediacy and clean attack of percussive elements in our music is sometimes frightening. The feather light foil used inside our stats has such a low mass, that we have nearly no compression at the leading edge of a tone or percussive event. These speakers are amazingly fast – the reaction they will show with a finger snap, piano attack or a side stick hit of a snare drum is incredible. Listening to a pair of Quad ESL 57 with a monitor style placement at nearfield distances is like using a gigantic Stax headphone system without the disadvantage of sound localisation taking place in your head, a typical problem of most headphones.The cleanness and cohenerence of the music makes us listen for hours.

A Quad ESL 57 can be your last loudspeaker.

So, a lot of space on this blog will be dedicated to the Quad ESL 57 and also the LS3/5a, the amplifiers to drive them, the analog frontend to feed them, the tubes, all of which gives you the feeling of being there and much more other fun stuff.

Stay tuned.


E. Strauss