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Linestage preamplifier


Ayon Audio

Manufacturer: Ayon Audio
Price (at the time of review, in Poland): 135 900 zł

Hart 18 | A-8101 Gratkorn | Austria


Product delivered for test by: Eter Audio

y memories from (I think) the first edition of High End Show in Munich (after it moved from Frankfurt's Kempinsky Hotel), survived in few „capsules”. Each of them contains a part of me, but also – as I can see it now – sort of prelude to the future events. That's what happened in 2005 in Munich where I met for the first time (among others) Mr Fabio Camorani, the owner of AudioNemesis, Ms Eunice Kron, chief of KR Audio, Mr Hervé Delétraz – the boss of darTZeel and many, many others. It was also then when I first talked to Dirk Sommer, who, at the time, was a Chief Editor of „Image Hi-Fi” (coverage HERE), and today is a Chief Editor of”.

All these people were really nice and friendly and I started a cooperation with some of them right away. One thing they all had in common was a certain reservation about Polish audio market and Polish audio journalist as they were all convinced that there was no high end market in our country. So they all suggested that if I wanted to review some of their products it should be rather something not too expensive. I mean, they all said that in a very nice, indirect way, but it was what they meant.
A year later even though I'd known many of them already for a year, their approach was still about the same. They were still nice, friendly and very professional but they still didn't see Poland as a market for their top products (coverage HERE).

In 2006 I saw something that really stayed in my head for a long time: products of Ayon Audio. And again, just like a representative of Soulution later, someone for Ayon (probably the owner, Gerhard Hirt, but it was a long time ago so I can't be sure) didn't really think that any of their products could be reviewed by “HighFidelity” in a foreseeable future. I was disappointed since I fell in love at the first sight with Spheris preamplifier presented this year. It looked great (you can see its picture in my Show coverage), sounded even better and immediately became my personal Holy Grail.

As it turned out less then ten years was more then enough to completely change the (audio) world. Most manufacturers I met then now are present on Polish market and for many of them Poland is the second biggest, and sometimes even the biggest market in Europe. Acrolink, who's representative (at the time), Mr Bé Yamamura, advised me strongly against even checking such expensive cables out, today sells kilometers of them in Poland, and I personally have four of their top power cables in my system. A Soulution power amplifier has been a part of my reference system for a few years now. And Gerhard Hirt is a friend and an honorary member of Cracow Sonic Society. What's more, his preamplifier, Polaris (only second to the top of the line, Spheris), has been my pride and joy for the last few years. We live in interesting times and it is (unlike the meaning of this saying in China) a good sign.
The Polaris preamplifier, in its few versions, has been a part, or rather a heart, the key element of my reference system since 2009, meaning since my review that was published in „High Fidelity” in April that year (issue No. 60, see HERE). Over this time it underwent several upgrades.

The version under review was already marked with number „II”. The gain stage was based on Siemens C3m penthode working in triode mode, it sported a tube power supply and a volume control based on step-up transformer. After the review I bought this device as I couldn't image my system without it. Some time later Gerhard with his engineers developed a completely new power supply, well – a power conditioner actually, still using tubes and generating high voltage sinusoid for signal tubes. Improvement of sound quality was significant but the character of the sound remained the same. I had no choice but to upgrade my preamplifier by purchasing the new power supply. The new version was now called Polaris III.

And I was happy. Until, in 2009, I listened to the top of the line Spheris II. This was a game changing experience despite the fact that I knew, more or less, what to expect. After this review, knowing I couldn't afford changing my Polaris III for Spheris II, I asked Gerhard if he could upgrade my preamplifier. It was a custom one-time job, and the result was called Polaris III [Custom Version]. The upgrades included changing all passive elements for the same as used in top preamplifier, and also upgrading few other details. Progress in sound quality was significant and while performance was still not the same as offered by Spheris, I was happy again.

But I knew then already that sooner or later I would have to get myself Ayon's top of the line preamp. So even when Ayon presented Polaris IV, despite the fact I appreciated another progress of performance it introduced, I still wanted Spheris III.
It took Ayon five years of hard work to develop improvements worth implementing. They concern mostly the volume control. It is still based on step-up transformers, but now these are controlled by sophisticated electronic system and contact relays instead of mechanical pot. Another element of this solution is an alphanumeric display on the front panel that allows user to read a current volume level.

The prototype of this device premiered in Munich in 2013 and the same unit was a part of a system awarded with Best Sound Audio Show 2013. It took Ayon another year to finalize the production of this device. I have received one of the first production units for a review. And it stayed for good…

Ayon Audio | CEO

Gerhard Hirt during Audio Show 2014, Warsaw (an away meeting of Cracow Sonic Society). Dirk Sommer, Chief Editor of whispering to Gerhard Hirt's ear.

In the year 2000 one of the developers of my single-ended amplifiers visited me with a prototype of a free-wired preamplifier mounted on a wooden board. He succinctly asked me to completely unbiased listen to “the thing”. It always was his hobby to make experiments with exceptional and crazy concepts (on this board he has worked secretly for almost 8 years, and he never mentioned about it) and he knew all our top preamplifiers very well we were distributing at that time. Actually he also made the service of all foreign brands.

But on this wooden board there were the cheapest components etc. and connections respectively and everything looked so different (even the C3m tubes) from a “normal” preamplifier which I was used to. Actually I did not really want to listen to this thing, but as luck would have it, my reference preamp struck and had to get the tubes changed.
What I heard then completely turned upside down all my imaginations of the previous preamps. Abruptly also tonally many things were different, an airiness, speed, incredible sound colors, plenty of transparency and deep dimensional picture and everything so tangibly true or a spatiality I did not know before - and this from a “wooden board model” with simplest components, barely enough to make it work.

Spheris I (first version, with small power supply) – High End 2006, Munich

I said to myself that in the design of preamps this happens only once every 20 years. We sat together and talked about a possible small limited series production, but first the wooden board had to give way to a real prototype housing and we needed an adequate power supply. Then we started working, first with the components. We started to change the components on a high level, but then noticed that this preamp (a special C3m triode/penthode design) reacted very stubbornly to components and hence again and again we had to listen to every component and try out new arrangements. The component-mix was very delicate and we reduced the unnecessary components wherever possible; but with every component less the total became “to the square” more difficult to master. Additionally also the C3m tube itself made life difficult: this posttube frivolously tends to microphony and therefore is difficult to handle for audio application. Its tonal properties are beyond any discussion, no small signal tube (e.g. ECC81, 82, 83, 88, 6SN7, 6H30 etc.) is able to hold a candle to it. For years we needed to reach deeply into our bag of technical tricks to eliminate this disadvantage. Until today we do not know, where someone seriously came to grips with this problem; however, immediately after the presentation of the Spheris there were 2 top preamps with C3m, but they disappeared after a very short time. I have also seen some “funny” power amps using a C3m as driver for the 300B, this never can work cleanly and satisfactorily.

Spheris I (second version, with large power supply)

5 more years passed until all critical points were finished or solved and the first serial Spheris was put on the market in 2005. We had never thought, that we had to go into so many uncharted waters to reach technical maturity; incredibly many difficulties as every piece in the preamp had a big influence on the sound, many in-house purpose-built items as the design was completely different from everything previously known; we even had to change the housing and the layout 3 times until we were completely satisfied.
But the first success of the Spheris showed us that we were absolutely right and over and over we were overwhelmed by the worldwide feedback. But they were 15 long painful years with many setbacks, until this concept could be developed from the first prototype design to technical maturity.
This stimulated us further to promptly improve the original design and its peripherals around this circuitry.
Another 5 years passed until the Spheris II appeared on the market in 2010; a completely novel tube power supply with re-generator (a re-generator which now was adopted perfectly to all internal operating voltages and we bypassed the bothersome re-transformation to 230 V as is necessary for traditional re-generators). And we developed chokes combined with film cap filtering, the peak of feasibility for a preamp power supply.

Spheris II

Then came the next milestone: the step-switched 4-channel ELMA volume potentiometer with 192 resistors of the Spheris I had to be replaced. There was only one acceptable solution: super-permalloy transformers placed on the output (not one resistor in the volume control system); an extreme challenge as here a completely different requirement (voltages) had to be considered; in the sense of being different from positioning the volume control at the input as is the case of almost every conventional preamps. We used up an enormous number of test equipment of step-up transformers until the right tonal combination of number of coils and transformation etc. became evident.
The Spheris II again set a landmark based upon the legendary Spheris I and was built for 5 years. By the way, every Spheris is assembled by hand and tested by only one person (no work-share with others) from A to Z. This assembly is extremely complex and a great challenge of craftsmanship.

Spheris III, prototype – Audio Show 2013, Warsaw

But there was still another „little something“ that annoyed us to make the Spheris II absolutely perfect down to the very last detail; we wanted a volume control without any mechanical switching support via potentiometer. The idea was to drive the 4 super permalloy step up transformers not by means of a mechanical potentiometer (Spheris II) but by a sophisticated electronic control system. Consequently, we needed an encoder instead of a mechanical pot, every single super permalloy transformer got its PCB with 24 reed relays each and an MCU with special software (i.e. in total 96 relays an 4 MCU components). This MCU receives the switching signals from the encoder potentiometer, processes them accordingly and with every operation always switches 8 relay contacts with a switching speed of 2/1000th seconds.
The development of this system took 3 years and even our digital specialists had to tackle this task to scrupulously adopt the software for the precise 4 time MCU-control! Thus, the most complex volume control ever incorporated into a tube preamplifier was born.
In 2014 at last the series production of the Spheris III preamplifier started.
As of today the Spheris III really nor reasonably cannot be improved anymore; it is matured in itself for almost 23 years and brought to perfection as perhaps no other series tube preamplifier on the actual world market.

Gerhard Hirt with Spheris III, prototype – Audio Show 2013, Warsaw

Ayon Audio in “HighFidelity”:
Integrated amplifiers
  • TEST: Ayon Audio CROSSFIRE III - integrated amplifier, see HERE
  • TEST: Ayon Audio SPIRIT III (NEW) - integrated amplifier, see HERE
  • KRAKOWSKIE TOWARZYSTWO SONICZNE: Spotkanie #79 – lampy Ayon Audio KT88sx, see HERE
  • TEST: Ayon Audio ORION II - integrated amplifier, see HERE
  • TEST: Ayon Audio SPARK DELTA - integrated amplifier, see HERE
  • TEST: Ayon Audio MERCURY II - integrated amplifier, see HERE
  • TEST: Ayon Audio 300B - integrated amplifier, see HERE
  • TEST: Ayon Audio ORBIS - preamplifier, see HERE
  • TEST: Ayon Audio Spheris II Linestage - preamplifier see HERE
  • TEST: Ayon Audio Polaris II - preamplifier, see HERE
Power amplifiers
  • TEST: Ayon Audio ORTHOS XS - power amplifier, see HERE
  • TEST: Ayon Audio VULCAN II - power amplifier, see HERE
  • TEST: Ayon Audio TRITON MONO - power amplifier, see HERE
Digital sources
  • TEST: Ayon Audio SIGMA - converter, see HERE
  • TEST: Ayon Audio CD-3s + NW-T - CD Player/DAC/preamplifier + audio files transport, see HERE
  • CRACOW SONIC SOCIETY: Meeting #80 - Gerhard Hirt and his S-3 (Ayon Audio), see HERE
  • TEST: Ayon Audio Skylla - D/A converter, see HERE
  • TEST: Ayon Audio CD-2s – CD Player, see HERE TEST: Ayon Audio CD-5s Special - CD Player, see HERE
  • TEST: Ayon Audio CD-1s - CD Player, see HERE
  • TEST: Ayon Audio CD-1 – CD Player, see HERE
  • TEST: Ayon Audio CD-3 – CD Player, see HERE
  • TEST: Ayon Audio CD-07 – CD Player, see HERE
  • INTERVIEW: Gerhard Hirt, Ayon Audio – Owner, see HERE

Nagrania użyte w teście (wybór)

  • Zapach psiej sierści, soundtrack, muz. Włodzimierz Nahorny, GAD Records GAD CD 019, „Limited Edition 500 Copies”, CD (2014);
  • Bill Evans Trio, Waltz for Debby, Riverside Records/Analogue Productions APJ009, "Top 25 Jazz", Limited Edition #0773, 2 x 180 g, 45 rpm LP (1961/2008).
  • Bing Crosby, Bing Crosby’s Greatest Hits, Decca Records/MCA Records, MCA-3031, LP (1941-1945/1977).
  • Chet Baker Quartet, Chet Baker Quartet feat. Dick Twardick, Barclay Disques/Sam Records, "Limited Edition", 180 g LP (1955/2011).
  • Cream, Disraeli Gears, Polydor/Universal Music LLC UICY-40023, Platinum SHM-CD (1967/2013).
  • Depeche Mode, Ultra, Mute/Sony Music Labels, Blu-spec CD2, (2007/2014).
  • Hans Theesink, Live at Jazzland, Sommelier Du Son sds 0016-1, 180 g LP (2014).
  • Leonard Cohen, Popular Problems, Sony Music Labels SICP-4329, CD (2014);
  • Ludwig van Beethoven, Sonatas op. 109, 110 and 111, piano: Evgeni Korolov, Tacet 208, “The Koroliov Series Vol. XVI”, CD (2014).
  • Miles Davis Quintet, Relaxin’ With The Miles Davis Quintet, Prestige/Universal Music LLC (Japan) UCCO-40005, Platinum SHM-CD, (1958/2013)
  • Pet Shop Boys, PopArt: Pet Shop Boys – The Hits , Parlophone/Toshiba-EMI TOCP-66252-54, 3 x CCD (2003).
  • Queen, Queen Forever, Virgin/Universal Music LLC (Japan) UICY-15347/8, 2 x SHM-CD (2014).
  • The Paul Butterfield Blues Band, The Paul Butterfield Blues Band, Elektra Entertainment Group/Audio Fidelity AFZ 187, “Limited Edition No. 0115”, SACD/CD (1965/2014).
Japanese issues available at

One can't really overrate preamplifier's role in audio system. From time perspective I can now see that preamplifier shapes the final sound in a way that is more difficult to perceive (unlike when one changes amplifier, speakers, or source). But it is a preamplifier that plays the key role, that sets a sonic direction for the whole system. In my opinion top models of speakers of most brands aren't really their best ones, when it comes to amplifiers and digital sources sometimes top models are the best and sometimes they are not, but when it comes to preamplifiers flagships always offer top performance.

Spheris III is not only Ayon's flagship linestage but it is also one of the best linestages I've listened so far to. What's more – the set of features it brings to the table, the way it shapes the sound of my system is almost perfectly “tailored” to my needs and expectations. In other words, Spheris III is a perfect addition to „High Fidelity's” reference system making it complete. I am sure that it is still possible to create even better device, and I am sure it will be developed. But I also realize that it will be very, very difficult and it will take a lot of time. How do I know that? Well, I've been waiting for Spheris III in its today's form for 10 years!

It's primary feature is sound's density. This element can be also interpreted as rich, mature sound, as the ability to convey the full body of each sound and not just its leading edge. It's like a coloring book for children, or a painting in its frame. The more of this “something” that fills the frame in, the better, the more natural, or should I say: the more palpable the content of it is. Using the word “natural” for anything coming from a system that only reproduces live music probably isn't really justified. Transferring a live event in 1:1 proportions to our home using any audio system is not possible.
What we get is always sort of approximation of reality and an artistic creation at the same time. People responsible for it are: musicians, producers, sound engineers, and also (especially when it comes to pop music) record labels. It so happens that we, audiophiles, attribute significant role also to companies manufacturing the final audio medium, or selling audio file.

Anyway the “naturalness” is one of key features of any audio system. But it is not that easily defined, its definition might change or “bend” in particular cases. Because since the reproduction of music in our home is sort of creation that imitates live event, this “naturalness” has to be different from the one of live concert. It has to appeal to our sensitivity to beauty.
Spheris III allows listener to hear or understand exactly what I am talking about. It adds some density, richness to the sound, it increases the depth of the sound. That means it modifies sound in such a way to fit a huge church, stadium, or a large club into a very limited space listener has in his room. I like that! That's what I want/need/expect. I think that this sort of sound modification is the right one for a high-end audio in general. It allows a system to convey more layers of music.

Another amazing feature of Spheris is how resolving it is. It was already an advantage of Polaris III. But having a chance to compare it with competitors like: Thrax Dionysos (see HERE), Robert Koda's Takumi K-15, or Mark Levinson №52 I realized that Polaris had its limitations. They didn't really bother me as they were a part of the whole sound concept that I liked, but I realized they existed. Top High end is about getting rid of any limitations, so surely I wanted these gone.

Spheris III in this aspect is a totally different device. Only the above mentioned Mark Levinson came close (among linestages I reviewed). And on top of that Ayon offered also this immense richness of the sound that Levinson couldn't quite match.
With Spheris there are large, very distinct, palpable, intense phantom images rendered in space. Each of them combines many layers that overlap one another to create something that I would describe as “natural” sound, assuming that “natural” means: causing impressions similar to those we experience during live concert. That means that this “artificiality” of music reproduction is somehow not an issue here. It is still not the same thing as “live music”, it is “an impression of naturalness”. One listens to the music and gets sucked in.

The reviewed preamplifier sports only a single gain stage using tubes. Such minimalist setups, especially one using tubes, are hardly something one would suspect of delivering a very focused sound and a truly deep bass at the same time. But that's exactly what this linestage delivers. It was were obvious with Soulution 710 power amp and Harbeth M40.1 and Trenner&Friedl Isis speakers. Both loudspeakers sport huge bass woofers so are well equipped to deliver even lowest bass notes. Bass not only went really deep, it was also amazingly rich, and it seemed to still have some headroom no matter how deep it went or how much energy was already released. That allowed the system to present more of other things – it conveyed acoustics of the recording in a better way, more dynamics shades, tiniest tone shifts and so on. Almost all other preamplifiers I know tended to homogenize those tiny differences.

It wasn't cold, emotionless sound that we get – unfortunately – from most passive preamplifiers or from sources with adjustable output signal level (with some exceptions like from: dCS and Ancient Audio). Those devices do homogenize those small differences to even larger extent. They don't really differentiate them, they try to “carve” those differences out and that has nothing to do with music, it might, at most, has to do with technical issues.

I've praised bass so much because this part of the range is a foundation for everything that happens up the range. Yes, there is a beautiful, colorful, rich and resolving treble that seems to be bit darker than with Mark Levinson №52. It is not as warm as absolutely exceptional (in this aspect) Tenor Audio Line 1, but to be honest I don't think I've ever heard something like Canadian linestage before. Ayon presents a slightly subdued picture comparing with a true world. It's like it was saving us something, like it presented to us only what it “believes” is good for us. That's a very subtle feature of this preamplifier but since on this level of top high end every little detail matters, getting it the way we want it costs a lot of money, I had to mention it for you to know what to expect if you plan to buy it for your system.

Before I wrote this review I had listened to Spheris III for a few months, using it in combination with different systems and different speakers. And before that I had listened to it couple of times during shows in yet another systems. So I could keep writing about it for a long time. But it would be pointless really – if you decide to treat seriously what you have already read, putting for a moment aside a reasonable approach of not completely believing in what you read (which is reasonable and understandable!), if you really ACCEPT what I've already written you already know almost everything you need to about this preamplifier.

And yet, I'd like to add a few words about soundstage. The whole idea of delivering a three-dimensional space via two speakers is somewhat artificial. When it comes to recordings done with microphones, i.e. with acoustic or electric instruments (the latter with their own sound sources like Leslie speakers for Hammonds, or guitar amplifiers, and so on), the space/soundstage is determined by the microphone technique chosen by a person conducting this recording. Whatever choices this person makes they always have some downsides, but they also have something that other techniques do not offer. Putting few techniques together will result in emphasizing some elements at the expense of others – that's how it goes. When it comes to studio recordings stereo effect is always in fact a realization of recording's producer vision.

It is sometimes hard to understand how in a particular case such a believable holography of the recording was achieved using such a unreliable means that producers had at their disposal. I'd say that we play some active role here too – we just got used to certain way of presentation and, unconsciously, we adapt to it by using or applying our experiences from concerts to what we can hear at home. It kind of replaces what we can really hear. It seems to work really well.
The micro-information about phase and level are conveyed by Spheris III in a uniquely good way. Only Mark Levinson and Thrax did something similar, but they were different in presenting other elements.

With Ayon soundstage becomes a part of the room and speakers are no longer perceived as sources of the sound. Even when the sounds came directly from the speaker, which happens with some stereo recordings from 50ties and 60ties, I could usually hear them BEHIND speaker, or from the same place in space where the speaker was. If the idea behind particular recording was to surround listener with the sound I truly felt surrounded with it. Sounds coming from behind my head? Absolutely and not only with Roger Waters' Amused to Death but also with some stereophonic Opus3 recordings and some others too. A dense, focused presentation.


It's the richness of the sound, its energy that makes this presentation so emotionally engaging. Almost every recording I listened to was an interesting experience assuming that music was actually interesting, of course. But even these bit boring, or those I'd been avoiding (for whatever reason) became interesting, involving. I can't really image a better recommendation for an audio product.

It is still not an “absolute sound”, as it doesn't exist, it's just an idea that everybody pursues. There are few more devices that I liked very much, each of them offering something that others didn't: Tenor Audio Line1 - richness and warmth, Soulution 720 amazing smoothness and coherence, Dionysos Thrax Audio consistency, richness and smoothness, and Mark Levinson offered it all plus remarkable openness in higher frequency and sheer energy in each sub-range.

The point is that each of us has to find his/her perfect fit, like a perfect pair of gloves that fit. If the fit isn't perfect it will bother you on some level and it won't matter whether there will actually be a problem with a glove or a hand. Spheris III is a perfect fit for me. I could easily enjoy music with every of the above mentioned preamplifiers and be really happy about it, but it is Ayon that comes closest to my personal expectations, that is the best “fit” for me and my system. And that's why it has become a part of my reference system. It allows my system to sound in a very pleasant, satisfying way, while still being a useful tool for a reviewer. It encourages me to listen without hiding weaknesses but also allowing me to ignore them. But it is ME who ignores them and not my system, it is my choice. That's the role of a reference system.


Development of current version of this preamplifier took 25 years – it is really hard to imagine – a quarter of a century! That also means 25 years of investing in a project – it took not only a lot of time but also effort and money. Spheris III playing music confirms in every millisecond that it's been a damn good investment worth every penny, sweat and minute spend on development. It is remarkable in every aspect. It offers its own vision of sound that is rather different then better than few other equally fantastic linestages.

This was a “no-brainer” for me. This device pushes all buttons inside my head that make listening to the music a pure pleasure and a challenge at the same time. This preamplifier works flawlessly with any power amplifier and any source. It is built of innovation and passion. And passion is a bonus we get with it, it is what makes it special and not just another product. This is priceless for every music lover.

The Spheris no. III repeats the idea Ayon used already in 2005 for version no. I – separate casings for power supply and the rest of the device. Starting with no. ‘II’ casing started to look similar to that of Polaris, i.e. with round corners and all panels made of aluminum. Also large chromed knobs are similar. These allow to select an active input, control volume and set balance between right and left channel. There is an additional element that makes it easy to differentiate Spheris from Polaris – all knobs have a round, red, backlit acrylic bands around them. The backlit can be switched off with a small switch placed on the back of the device. It is so discrete though that I never felt a need to do so. On a front panel there is another new element – a small alphanumeric display showing current volume.

This last element make you wonder – why there is exactly the same knob for volume control taken from version ‘II’ that sports a large dot that help you to recognize the position of this round knob. This dot was useful before but now the knob controls encoder and just turns round and round. So in fact this dot misleads user. There are two small red LEDs next to the knob that indicate that device is on (same as those red bands around knobs) and the other shows when „mute” function is active.

The back panel looks very nice. There are two rows of RCA sockets and XLR input and output – it is a fully balanced device. There are six inputs – one balanced and five unbalanced, and as many as four outputs – one balanced and two unbalanced (with adjustable signal level), and one tape out that might be also use to send signal to headphone amplifier. But to use it the device must be on.
Sockets are arranged in a different way than in previous versions – before Gerhard used Audio Research's system, with right (red) channel on top, and left (white) below. Most manufacturers use opposite arrangement and this device also uses it.

All electronic circuits are mounted on few PCBs. The most important of them are the ones with four horizontally mounted Siemens C3m penthodes – the ones in my unit were made before II World War and come from a supply of German post. Each of them works in triode mode, a pair works in each channel – as channels are balanced they require two tubes for right and two tubes for left channel.

It is amazingly simple circuit, at least if we consider only a signal transfer. Signal goes from inputs to the PCB with relays. Then, with cables, it goes to the front of the device, to four (two per channel) transformers with multiple tappings. Signal level is changed via change of ratio between primary and secondary winding. It is the same solution as the one used in Music First Audio preamplifiers for example.

Transformers with classic core are made by Ayon in-house, and to switch windings they used an innovative system of relays instead of mechanical switch they used previously. And finally signal reaches tubes, and than the output via a single large Mundorf MCap Supreme Silver/Gold capacitor. All passive elements were carefully selected during listening sessions and all, obviously, are high class ones. There are Lundahl transformers in the input section – signal from RCA inputs is symmetrized and then processed in balanced form. The power supply sits in a separate casing but its small part is located in the main casing of the device. There is a large Lundahl choke and two huge polypropylene capacitors that are a part of power supply circuit for anode. There are no electrolytic capacitors in tubes' power supply circuit.

The main unit is connected with external power supply with a multi-core umbilical. Cable for Spheris III is more flexible and it sports much larger plug than the one for Polaris III (have a look at the picture in the gallery).
Power supply sports two large (I mean high-power amplifier large) toroidal transformers, shielded with metal covers. The anode voltage is rectified in CV135 tubes, full-wave rectifier, with polypropylene capacitor following. As you can see both channels use the same power supply. It seems that the second transformer supplies a large PCB at the back of main unit's casing, that transforms voltage from power grid into pure sinusoid @ 60 Hz. You can see this value displayed on the front panel of the device. Only this “re-generated” voltage is sent to transformer that supplies power to the main unit. This whole circuit is called: AC~ ReGenerator.

This device has a classic Ayon's looks with extremely solid casing, engraved writings on it and anty-vibration feet. It still benefits from a good anti-vibration platform and even more advanced feet – I use Franc Audio Accessories Ceramic Disc Classic. The whole electronic circuit seems very simple from electric point of view but its execution is very complex. Power supply itself is as important as the circuit supplying it.

Spheris III comes equipped with a simple, small remote control that allows user to change volume and use a „mute” function.

Specifications (according to manufacturer)

Class of operation: class A/triode
Tube complement: C3m
Maximum output (@ 1 kHz ): 40 V rms
S/N ratio: > 98 dB
Input impedance: > 1 MΩ
Output impedance: 30 Ω
Frequency response/Line: 0,5 Hz – 500 kHz
Harmonic distortion (@ 1 V) Line: < 0,01%
AC~ ReGenerator: max. 300 W
AC~ ReGenerator frequency: 60 Hz
Dimensions Pre (WxDxH): 500 x 430 x 110 mm
Dimensions ReGenerator (WxDxH): 500 x 430 x 110 mm
Weight (pre & power supply): 43 kg



- Turntable: AVID HIFI Acutus SP [Custom Version]
- Cartridges: Miyajima Laboratory KANSUI, review HERE | Miyajima Laboratory SHILABE, review HERE | Miyajima Laboratory ZERO (mono) | Denon DL-103SA, review HERE
- Phono stage: RCM Audio Sensor Prelude IC, review HERE

- Compact Disc Player: Ancient Audio AIR V-edition, review HERE
- Multiformat Player: Cambridge Audio Azur 752BD
- Line Preamplifier: Polaris III [Custom Version] + AC Regenerator, regular version review (in Polish) HERE
- Power amplifier: Soulution 710
- Integrated Amplifier: Leben CS300XS Custom Version, review HERE

- Stand mount Loudspeakers: Harbeth M40.1 Domestic, review HERE
- Stands for Harbeths: Acoustic Revive Custom Series Loudspeaker Stands
- Real-Sound Processor: SPEC RSP-101/GL
- Integrated Amplifier/Headphone amplifier: Leben CS300XS Custom Version, review HERE
- Headphones: HIFIMAN HE-6, review HERE | HIFIMAN HE-500, review HERE | HIFIMAN HE-300, review HERE | Sennheiser HD800 | AKG K701, review (in Polish) HERE | Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, version 600 - reviews (in Polish): HERE, HERE, HERE
- Headphone Stands: Klutz Design CanCans (x 3), review (in Polish) HERE
- Headphone Cables: Entreq Konstantin 2010/Sennheiser HD800/HIFIMAN HE-500, review HERE

- Portable Player: HIFIMAN HM-801
- USB Cables: Acoustic Revive USB-1.0SP (1 m) | Acoustic Revive USB-5.0PL (5 m), review HERE
- LAN Cables: Acoustic Revive LAN-1.0 PA (kable ) | RLI-1 (filtry), review HERE
- Router: Liksys WAG320N
- NAS: Synology DS410j/8 TB
System I
- Interconnects: Acrolink Mexcel 7N-DA6300, review HERE | preamplifier-power amplifier: Acrolink 8N-A2080III Evo, review HERE
- Loudspeaker Cables: Tara Labs Omega Onyx, review (in Polish) HERE
System II
- Interconnects: Acoustic Revive RCA-1.0PA | XLR-1.0PA II
- Loudspeaker Cables: Acoustic Revive SPC-PA

System I
- Power Cables: Acrolink Mexcel 7N-PC9300, all system, review HERE
- Power Distributor: Acoustic Revive RTP-4eu Ultimate, review HERE
- Power Line: fuse &#8211; power cable Oyaide Tunami Nigo (6m) &#8211; wall sockets 3 x Furutech FT-SWS (R)
System II
- Power Cables: Harmonix X-DC350M2R Improved-Version, review (in Polish) HERE | Oyaide GPX-R (x 4 ), review HERE
- Power Distributor: Oyaide MTS-4e, review HERE
- Stolik: SolidBase IV Custom, read HERE/all system
- Anti-vibration Platforms: Acoustic Revive RAF-48H, review HERE/digital sources | Pro Audio Bono [Custom Version]/headphone amplifier/integrated amplifier, review HERE | Acoustic Revive RST-38H/loudspeakers under review/stands for loudspeakers under review
- Anti-vibration Feets: Franc Audio Accessories Ceramic Disc/ CD Player/Ayon Polaris II Power Supply /products under review, review HERE | Finite Elemente CeraPuc/ products under review, review HERE | Audio Replas OPT-30HG-SC/PL HR Quartz, review HERE
- Anti-vibration accsories: Audio Replas CNS-7000SZ/power cable, review HERE
- Quartz Isolators: Acoustic Revive RIQ-5010/CP-4

- FM Radio: Tivoli Audio Model One