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D/A Converter

Price: 25 000 zł

Distributor: Nautilus Hi-End

ul. Malborska 24, 30-646 Kraków
tel./fax: 12 425 51 20/30
tel. kom.: 507 011 858



Text: Wojciech Pacuła

Translation: Marek Dyba

When I spoke during this year's High End exhibition in Munich (report) with Gerhard Hirt, the owner of Ayon Audio, Vaic and also distributor ofLumen White, I could not notice that he was particularly proud of three products: CD Player CD-5, D/A Converter Skylla (both Ayon Audio) and Lumen White turntable. Quite a wide spectrum of products – digital sound on one end, analogue on the other, but only one common goal – music presented in the best possible way. As far as the world of vinyl records is quite new for Mr Hirt (if we forget the fact that his preamplifiers included also often wonderful phonostages, than above mentioned turntable would be his first trip towards analogue sound), but the digital sound was his priority for couple of years now. He started with the line of CD players: CD-1, CD-2 and CD-3, that showed the direction of his future research. Yes, research, because Compact Disc standard, even though it's been on the market for years, only now is reaching its prime time and becomes to show its high-end's aspirations. And that regardless of present mood of analogue fans. There are a lot of possible areas for exploration – transport mechanism, digital filters, analogue circuit, power supply circuit. Yes – every element has been researched, developed and improved.

Lets start with the transport mechanism. At the beginning Gerhard was using Sony's transport mechanisms with KSS-213 laser, that had been designed for CD players in the golden age of CD. It is worth mentioning that it is still used nowadays by for example Accuphase. But when it came to renewing of all the line and the CD-1 entered the market it was completely redesigned – the transport mechanism was changed to Sanyo, but the software was developed by former Philips engineers, who now offer their services to all Customers. So no wonder that for the newest model - CD-5 Mr Hirt decided to use the best or at least one of the best systems available – newest version of LH (it is M version with RoHS certificate) - CD-Pro 2 from Philips. All above mentioned CD Players are top-loaders. This review is about D/A converter so there is no transport mechanism and we can discuss it only as external device that might be connected to this DAC. That is why when developing this product companies research focused on other areas of interest – digital processing, analogue output and power section. For digital section they used their experience gained when developing CD-2, in which a new upsampler was implemented, converting signal to 24/192. Quite unexpected was the choice for D/A chips – they decided for Burr-Brown PCM-1704, fantastic 24/96 chips, even the more expensive version ‘K’ – carefully selected and matched. The only problem is that this chip is no longer in production. The output is based, as it usually is in Ayon's products, on Sovtec's 6H30-EB triodes. And finally power section. Here they used experience from their work with CD-3, where rectifiers were used for output tubes, and also – probably they took even more from – enhancements from preamplifier Polaris II. They decided to use four 6X4 tubes to create a full-wave rectifier. Unlike in the above mentioned CD player, for new CD-5 and Skylla, which in fact is DAC from CD-5, they decided for one chassis and no separate one for power section. The voltage is delivered by three expensive R-core type transformers. The device has been equipped with couple of different inputs: I2S, USB, S/PDIF and AES/EBU, but also with volume control and two analogue inputs which makes Skylla the true sound managing unit.

So far we tested following AYON products::
CD Player Ayon CD-1
CD Player Ayon CD-3
Integrated amplifier Ayon 300B
CD Player Ayon CD-1s (w systemie)
Preamplifier Ayon Polaris II


Discs used for listening sessions:

  • Carol Simpson, „Live” and Otherwise, Sinatra Society of Japan, XQAM-1032, CD.
  • Bill Evans, You Must Believe in Spring, Warner Bros./Warner Music Japan, WPCR-13176, SHM-CD.
  • Pat Metheny Group, The way Up, Nonesuch, 79876-2, CD.
  • Charlie Haden&Antonio Forcione, Heartplay, Naim Label, Naim CD098, CD; review HERE.
  • Camouflage, Relocated, Vision Music, CDVM019, CD.
  • Porcupine Tree, The Incident, WHD Entertainment, IECP-10198, 2 x HQCD.
  • The Beatles, 09.09.09 Sampler, Apple/EMI, 84414 2 5, 2 x CD; review HERE.
  • Johny Hartman, Just You, Just Me…, Regent Records/Columbia Music Entertainment, COCB-53522, CD.
  • Kazumi Watanabe, Jazz Impression, Eve records, EWSA 0163, SACD.
  • Pliki FLAC and WAV 24/96, 24/192.

Austrian converter Skylla offers incredibly full, rich sound. And vibrant. With great resolution. On one hand I should be surprised as already mentioned CD-3, as interesting in many aspects as it was, offered quite an opposite. But since I listened already before to CD-5 when reviewing it for „Audio” , what I heard now was just a confirmation of what I already had learned: Gerhard Hirt achieved something others fight for two, three times longer. He managed to merge some elements present only in high-end equipment at the level of DP-700 Accuphase, Lektor Prime and Lektor Grand SE Ancient Audio, just to mention the best examples that come to my mind at the moment. It is like a microscope with a soul, or a guy at the other end of the microscope eyepiece. Wow, how wonderfully sounded recently acquired recording of Kazumi Watanabi Jazz Impression! This Japanese jazz guitar's virtuoso, spiritual brother of Wes Montgomery and Joe Pass, played in very full, even terse way. There was no tube's warmth or hardness. Both of those occur when some tube elements are in the signal's path, but they are nothing else but distortions. I am probably used to the sound of Sovtek's 6H30, because I have the same ones in my Lektor Prime, but I heard several semi-conductor's players too, so even if I really have my own standard imprinted in my mind, it's been surely ameliorated by exposure to different sound signatures.

Let me repeat – it is a surprise to find such a merge of outstanding timbre and vibrancy of the sound. Sound signature is very, very similar to the Prime's. There are some differences but really minor ones. And that tells a lot about this DAC. Voices float freely between loudspeakers – both male like captivating velvet voice of Johny Hartman at Just You, Just Me…, and female like sensual Carole Simpson at “Live” (and otherwise). The balance between warmth and sensuality is correct which makes the sound plausible. It is not a very „handy” category, as we enter the area of artistry, perception of music, how real is what we hear. In perfect conditions, meaning live concert, we can evaluate ambience of the place, work of sound engineer and how fit are the performers at the time. When you listen at home it is about something above that – it is about how exact is the reproduction of the recording. The less important the „fidelity” factor is, the more we concentrate on same things as during live concert, the more deeply can we experience the sounds, the music. I think that Skylla, and CD-5 are very close to the ideal. It is still a reproduction but so plausible that we can „drift” into it, experience the music. That's what happened with Hartman and Carole Simpson. Those recording restored by Sinatra Society of Japan have high historical and aesthetic value – it is about the music after all. Sound quality is rather mediocre. Except for piece Nb 8 called Fly Me To The Moon. That is a classic known mainly due to Sinatra's interpretation, here recorded in a perfect way – not just as a recording done fifty years ago but just as any recording. Skylla presented easily full, mellow sound of the piano placed bit in the back and Simpson's voice in the front – sensual, bit oniric, not too joyful. Listening to the next song with much lower sound quality didn't cause frustration. My impression was similar to this from live concert – different performer, or change of sound engineer – I knew something changed, and knew what changed but perceived it as part of the show not as some error.

It was kind of digging in the old stuff but allowed me to appreciate mastery of the engineers involved in this project. I was also most impressed by the sampler with remastered stereophonic recordings of The Beatles. When reviewing this recording some time ago right after I received it I pointed out astonishing clarity of the sound combined with great timbre. Now I can only confirm that! Skylla went even deeper into this universum than my Prime. Yes, sadly I have to admit that. The difference wasn't big – the sound came from even darker background and it was even richer. This would have its price – to the value of DAC you would have to add a cost of good digital cable (Acrolink Mexcel 7N-D6300 or at least 7N-D5100, the latter was used during this test), plus price of a good transport and proper power cord for it. But in return we will get something absolutely amazing. Prime did a great job as a transport, same goes for CD-5 (they both have the same transport mechanism inside - CD-Pro 2 LH Philips). There is an option for improving sound quality at pretty low cost: Skylla has I2S input, and CD-5 has such an output. I am pretty sure that soon we will see a new transport made by Ayon with I2S output. I remember very well all the players with separate transport that used I2S connection and it always sounded superior to S/PDIF. Unfortunately I didn't have proper cable at the time of this review so my opinion is just an extrapolation of my experiences with other players. You could try Skylla for example with North Star Design transport that is equipped with such an output.

Coming back to The Beatles – the sound that I heard was very real, almost perfectly real! I listened to similarly rich sound at the same price level before from McIntosh MCD501, but Skylla presented trebles in a better way and differentiated instruments much better. To verify the sound of bit heavier music I listened to recently released CD of Porcupine Tree The Incident. Leaps of dynamics, piano and forte, strong electric guitars, acoustic guitars, great voice. Overall it is hard to call that a masterpiece of sound engineering, especially if we compare it with how jazz recordings are done, but if we compare to other rock recordings we will find this one as a very good one. Skylla softened leaps of dynamics a bit. I couldn't hear it before but obviously DAC softens strong impulses. The effect is very pleasing as we have everything under control but I had to mention what it does. I really loved the sound of voice – it was rich, pleasant and in great proportion with instruments. The scale was also greatly presented – in was not a small pin between guitars but a full scale source of sound. And finally some electronic music - Reloaded Camouflage. Same impressions as with the previous recording – rich, warm sound, some softening of dynamics, bit stronger lower midrange. In other word extremely pleasant sound.

I should try to benchmark Skylla (and CD-5 as the sound is very similar) with other good digital sources. I think that the depth of the sound, its scale, timbre, differentiation put this DAC slightly – in the high-end world „slightly” might have a great meaning – above present version of Lektor Prime Ancient Audio. My player shows more of what is going on between sounds, while Ayon homogenizes that a bit, increasing in this way the size of instruments. Prime is thereby bit more precise showing their contours. But interestingly it doesn't make the sound more realistic or plausible – it is just another way of presentation. Accuphase's DP-700 presentation is maybe a bit more sophisticated, mostly by smoother attack with better resolution. The sound is slightly warm but surely less warm than the one from Skylla. It controls bass bit better and it goes deeper. On the other hand Lektor Grand SE Ancient Audio has better resolution and differentiates better recordings, instruments, voices and so on. Not much of a difference but still it shows that there is some room fro improvement for Ayon. Similar sound as tonal balance is concerned you can find in Reimyo CDT-777+DAP-999EX and Jadis JD1 MkII+JS1 MkIII - I reviewed them both some time ago. It is a good direction – those two together with Grand SE are in my opinion best digital players (including CD, SACD and DVD-A) that I ever listened to. Ayon lack bit of their depth, resolution and softness, but it costs five or six times less…


Because, as mentioned already, I reviewed simultaneously also CD-5, for „Audio” I was able to explored all features of Skylla – and those are pretty impressive. Both devices are very similar so I can repeat what I sent already to „Audio”. Ayon's converter can be used as analogue preamplifier and as D/A converter - preamplifier. After connecting to Skylla some analogue sources, like turntable, you will find that proper A/D conversion, volume reduction and than D/A conversion can give some quite nice effects. Surely the resolution of the recording is degraded and sound looses its „colors”. But if you want to connect some auxiliary source like a tuner it shouldn't be a problem – quality of the sound should be good enough to allow pleasant listening. But if you want to plug in mid-class turntable I suggest buying an external phonostage. S/PDIF input proved that Ayon is a great D/A converter as long as we don't use volume control. Admittedly it is quite decent like the one in Accuphase’s players, but it doesn't stand a chance when comparing to digital volume control in Wadia, not to mention those in analogue preamplifiers. Signal from Digital Static Streamer DSS 30 by Blacknote, with 24/96 material sounded fantastic, in fact it significantly bettered sound from devices own converter (that is also based on tube technology). I got all advantages of CD sound plus much better resolution and lower bass - outstanding!

On the other hand USB input turned out to be only partially successful. Specialized USB converters by Wavelenght (they licensed their technology also to Ayre), with particular software (we already reviewed Brick and Cosecant v3), work in asynchronous mode. Their sound can be described simply as high-end – better then from any optical medium. But in Ayon they used quite old Bur-Brown chip, model PCM2704. That is not the best option (it's the worst one to be honest). In this case the circuit is synchronized with computers clock. But the latter changes all the time, following the signal that is sent in packets, depending on what is computer doing at the moment. Changes of sampling rate happen every millisecond adapting to average clock value – that is why it is called „adaptive mode”. Result is a huge jitter. And you can't use hi-res files – it supports up to 16 bits and 48 kHz. Newest chips like Texas Instruments TAS1020B allow much more – it accepts signal up to 24/96, and you can also reprogram them so that they work in asynch mode. There is a on-chip memory buffer – signal goes there first and is recklocked independently from computers clock. So that is probably the reason why hi-res files from my laptop (HP Pavilion Entertainment PC, Vista) didn't sound that good as same music from CD. Difference wasn't that big but still the perspective and dynamics were bit flattened. Timbre of the sound was very nice though. I couldn't tell the difference between ‘hi-res’ 24/96, 24/192 material) and ‘standard res’.

Shortly about up-sampling. Turning it on gives better timbre of the sound, adds mass to lower midrange, and the whole sound becomes more smooth. Those are clear advantages for the most recording because what you get becomes quite similar to the sound from vinyl record. But few recordings will sound better without up sampling. With up-sampling off sound becomes more „raw”, not so rich but more precise. So if you listen to some Naim recordings, or old ones from 50's, it is worth trying – for those recordings up-sampling is not necessary. I had similar experience with Jadis system but there up-sampling was required almost all the time. Here – it is just one of the possibilities, a digital filter that we might use to change the sound of our recordings.


Skylla is a powerful device, equally impressive as simultaneously introduced to the market CD-5 player. The only thing that differs Skylla from CD-5 in no transport mechanism. Skylla benefits from better power supply circuit as one of the transformers doesn't have to serve transport mechanism. The Skylla's chassis is much bigger than the ones of CD-1 or CD-2. It is even bigger than Accuphase’s.DP-700 Its size is matched to the size of Polaris II preamplifier. The back panel looks like from a well equipped preamplifier. Two analogue outputs (RCA and XLR) at the both sides of the panel - you have to choose which one will be used with a little switch (the not used is off). There is another switch that allows to choose between variable output level – max of 4 V rms, 6 V rms or 9 V rms. CD-5 offers only two levels 4 and 9 V rms. In the middle of the panel there are analogue and digital inputs and digital outputs as Skylla might work also as well equipped preamplifier with great D/A converter (A/D converter as well as you can get a signal from analogue input at digital output).

There are two analogue inputs (two pairs). Signal goes to Burr-Brown PCM4202 chips. It is a very good 24/216 chip with great parameters. The PCM4202 architecture utilizes a 1-bit delta-sigma modulator per channel. It supports 24-bit linear PCM output data, with sampling frequencies up to 216kH. There are several digital inputs: double S/PDIF (RCA), TOSLINK, AES/EBU (XLR), I2S (Ethernet type – same as in North Star Design products) and USB type B. There are also two digital outputs – S/PDIF (RCA), and AES/EBU (XLR). There is a red LED next to IEC showing if the phase is correct.

At the front there is quite big red display (dot-matrix type). It will display information regarding selected input or the volume level. Unfortunately that last info you will get only when you press a button. I think it should be displayed all the time like in Ancient Audio players. I would gladly see an information regarding the digital signal delivered to DAC – if that is 16/44 or 24/96. It is important as the operating system of the computer often forces some sampling rate and we can't easily verify what we get. Next to the display there is a red LED „24/192” that shows if the up-sampling is on. A metal remote control looks very nice but it is totally impractical – there are 32 buttons of the same shape and size. Its main advantage is that it is a system's remote control – CD, preamplifier, integrated amplifier, DAC (Skylla).

We will find a lot of tubes inside Skylla. In the output there are two for each channel double „super-triodes” 6H30, that were used some time ago exclusively by Ministry of Defense of Soviet Union, and later by American BAT. Now this tube is available to all interested parties – it is manufactured by Russian Sovtek. All tubes are placed on one big PCB. Only high quality elements were used, like metalized precise resistors, and fantastic coupling capacitors. The latter have tremendous influence on the final result – I took part in many auditions comparing different types of capacitors from different manufacturers, and the differences were not just significant – they sometimes were decisive if the device was great or no good at all. In Skylla and CD-5 we get something special – both in the output stage and in power section they used expensive Mundorf MCap Supreme capacitors with quite big capacity of 3,3 uF.

There are four rectifiers - 6X4 NOSes from Chinese production – together they built up a full-wave rectifier. The voltage powers output tube's anodes. In the complex power section we shall find three R-core type transformers, made in Japan by Kitamura Kiden. Both Mudorf capacitors and Kiden's transformers are made „Exclusively for Ayon Audio” and carry Ayon's logo. Anyway power section is surely outstanding. There is a separate transformer for analogue stage (both channels), another for digital section, and the third one probably for input section. In the first stage large polypropylene capacitors are used just like in Conrad-Johnson's devices. There is also dual choke and AC filtered power supply. D/A converters are a different story. There are some commonly praised chips like Philips TDA1543 or Burr-Brown PCM1704. The latter is a multibit BiCMOS converter, that hit the market precisely on July 25th 1998 and currently already out of production. These are the real KINGS of NOS DACs. Gerhard managed to pull off something even more crazy – he acquired a lot of PCM1704K. „K” means these are specially selected chips with best parameters. Chip accepts signals up to 24/96. Both CD-5 and Skylla are equipped with upsampler changing the signal from CD to 24/192. Same thing is done with the signal from digital inputs. The interesting thing is that PCM1704K works up to 96 kHz… But obviously there is a possibility to turn off eightfold oversampling and make him accept higher frequency signal. Anyway we have four chips – two for each channel. Before signal goes to PCM1704K it is transferred via Burr-Brown's SRC4193. Than signal goes to modern, programmable DSP Seiko NPC SM5847 chip that is working as a precise signal strength control. This chip is employed also as digital filter as PCM1704 DACs don't have their own filters.

As mentioned before there are also two analogue input (in Skylla and CD-5) – signal from them is buffered in Burr-Brown chips, and than turned into digital form in A/D PCM4202 (24/216). USB input is served by not too good BB PCM2704 chip that limits signal to 16/48 – what a pity! All they had to do was to use FireWire input that is used for example by Swiss Weiss in their Minerva DAC. This kind of connector is commonly used in most modern laptops. Of of the important goals of the designers was proper vibration dumping – chassis is made of beautifully crafted high grade 12mm aluminum -brushed and black anodized. It was made in China. There is no reason to hide that fact. There is another company on the market – Chinese Raysonic – that uses almost identical chassis. In fact it is a brand that was created by the manufacturer of Ayon's chassis… The device is supported by solid absorber aluminum feet with superior damping characteristics.

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  • CD player: Ancient Audio Lektor Prime (tested HERE)
  • Phono preamp: RCM Audio Sensor Prelude IC (tested HERE)
  • Preamp: Leben RS-28CX (tested HERE; soon to be changed to Polaris II, tested HERE)
  • Power amp: Luxman M-800A (tested HERE)
  • Integrated amp: Leben CS300 (reviewed HERE)
  • Loudspeakers: Harpia Acoustics Dobermann (tested HERE)
  • headphones: AKG K701, Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, 600 Ω version (reviewed HERE, HERE, and HERE)
  • interconnects: CD-preamp: Wireworld Gold Eclipse 52 (tested HERE; soon to be changed to Acrolink Mexcel 7N-DA6300, article HERE), preamp-power amp: Velum NF-G SE (tested HERE)
  • speaker cable: Velum LS-G (tested HERE)
  • power cables: Acrolink Mexcel 7N-PC9100 (CD; reviewed HERE) and 2 x Acrolink Mexcel 7N-PC7100 (preamp, power amp (reviewed HERE)
  • power conditioning: Gigawatt PF-2 Filtering Power Strip (reviewed HERE)
  • audio stand Base
  • resonance control: Finite Elemente Ceraball under the CD (article HERE ) Turntables change continuously, as do cartridges. My dream setup: SME 30 with Series V tone-arm and Air Tight PC-1 cartridge (also in the PC-1 Mono version).