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August 2014
Life's easier for the big
guys. Starting from kindergarten, through primary school and into the business
world. And here we have the Ayon Audio Sigma DAC with preamplifier in for
review, which is a culmination of years in design and engineering. And like with any other
business, the principle also applies to the audio industry, including its
passion-driven "audiophile" segment. Using the "mass scale" effect, big
companies can offer products at a much lower price than small, specialized
manufacturers. There are obviously downsides to this mass production approach.
One of them being impersonal nature of the product such as found within the Ayon Audio Sigma
DAC as reviewed here. On the other hand, the
benefit of being the big guy is to have big money available. And big money
translates, among other things, into more funds for investment and research.
Hence, large consumer electronics companies are playing a vital role in bringing
new and innovative solutions to the market. Let's not be na๏ve, they are the
real driving force for this industry and it is their solutions that keep pushing
it forward. Perfectionist audio has a different role. Its objective is to
refine and perfect what has been developed by those with the necessary financial
resources, and to translate it to the "language" of audiophiles who insist on
truth at any cost. And we are speaking here in the language of the absolute.
Hi-fi and high-end audio has its comfortable and quiet niche, like tube
amplifiers and turntables, long since abandoned by the mainstream consumer
electronics industry. There are also areas where it needs to constantly keep up
with the market leaders, especially in computer audio. Here competition is
life-and-death and everyone is fighting to be first in line. Big audio
companies, like Marantz, are more successful in that regard. But if you are a
specialist in a given area, or can afford to hire such specialist, you can take
on and outdo even the biggest guys. When Michal Jurewicz, the owner of Mytek
Audio, told me that he was developing a DAC that accepts the DSD signal with
quad sampling frequency the upper limit currently used in the recording
studios it seemed to be an exaggeration. Any reasonable person would say
that double rate, i.e. DSD128, is absolutely sufficient and that Mytek is still
ahead of the game with its Stereo 192-DSD DAC. He turned out to be right. Just
before I received the Ayon DAC, I finished a review of several systems with
planar magnetic headphones, including the HA-1 headphone amplifier with USB DAC
and the PM-1 headphones from Oppo. The HA-1 is currently the most advanced DAC
on the market, accepting quad rate DSD (DSD256) and PCM DXD (32-bit/384kHz). Ayon Audio from Austria is a company with a well-established
tradition, which has built its reputation on high-end tube amplifiers and
preamplifiers. When the time came, it started offering CD players. They were
characteristically shaped top-loaders with a tube output stage. Nothing has
since changed in this regard, except for one thing: all Ayon digital sources
today come equipped with digital inputs, including USB. The company's lineup has
also been extended to include D/A converters. At this moment, the company from
the Austrian city of Gratkorn has three DAC models in its product lineup the
flagship Stratos, the less expensive Stealth and the newest and most affordable
Sigma. The two former are the second generation products while the latter is an
absolute novelty with no previous counterpart.
Design The Sigma is a D/A converter with built-in preamplifier. Since
there is no information in the company literature whether it is an analog
preamplifier, I assume that it uses digital volume control integrated in the DAC
chip. It accepts PCM signal up to 32-bit and 192 kHz, and DSD64 and DSD128. I
would normally add here that DSD is only supported via USB. However, Gerhard
clearly seems to have a weak spot for this format, inherited I presume
from his meetings and conversations with people involved in the recording studio
and analog technology. My guess would be that the person who is in some way
responsible for that is Dirk Sommer, the editor-in-chief of the German magazine HiFiStatement.net. The DSD signal can be, of course, fed in via USB, which is
now standard. The Sigma adds to that a whole array of DSD-enabled inputs,
including a RJ45 port, typically used for Ethernet and here used for DoP
streaming, and BNC connector, which can both be used to stream the DSD signal
from the Ayon NW-T network transport. But there is also a DSD interface on three
BNC connectors, taken straight from the recording studio. The PCM signal can be
sent through RCA and BNC coaxial inputs, XLR AES/EBU and optical TosLink inputs,
as well as an I2S input on another RJ45 port. The latter is supported
by both the NW-T and the CD-T transport. The Sigma can be hooked up directly to a power amplifier as it
has a preamplifier on board. The output signal on the XLR and RCA outputs can be
set to "High" (+6 dB) or "Low" (0 dB), selectable by a toggle switch. Another
toggle switch selects between "Normal" and "Direct Amp" analog output mode. The
latter automatically brings the output level down to -40 dB on each power-on,
which is useful to protect the power amp and speakers. If you do not use the
pre-amplifier section, pressing an appropriate button on the remote control unit
bypasses the attenuator circuit. There are two more switches, one per each
channel, that are hidden at the bottom of the DAC case. They can be used for
another 6 dB of gain reduction with high sensitivity power amplifiers, to
eliminate hum and noise generated by the Sigma output tubes. The remote control
unit itself is fairly typical for this manufacturer, with a metal top and
plastic bottom. It is not particularly user friendly or best-looking, but one
can get used to it. You better not lose it, though, as it is the only way to
activate the upsampler (24-bit/192kHz) and choose between the two digital output
filters. "Filter 1" is a slow roll-off filter with no phase shifting and
pre-ringing; "Filter 2" is a classic brickwall-type filter with symmetrical
oscillations or ringing before and after the transient. The electronic circuit is mounted on three PCBs, separate for
each section. The largest board houses the actual D/A converter with its power
supply and a regulated DC filament supply for the output tubes. The tube output
circuits, including analog filters and a gain stage, are mounted on two smaller
boards. One of them also contains the plate voltage supply circuit using a
rectifier tube. The USB interface is built on a small PCB, mounted to the main
board. It sports an XMOS chip with two very nice quartz oscillators, thermally
and mechanically compensated. They clock the output signal, separately for the
44.1 and 48 kHz sampling frequency families. The XMOS chip has its own clock
oscillator. The DAC chip is ESS ES9018S Sabre32, recently very popular in
inexpensive and very expensive converters. It is used here in an 8 mono to 2
stereo configuration, with four D/A converters per channel. The flagship Stratos
sports two such chips for a 16 mono to 2 stereo configuration. The chip is
clocked by another great looking clock oscillator, with fantastic Sanyo
capacitors in its power supply. The I/V conversion is performed by Burr Brown OPA2134 op-amps
mounted in IC sockets. The circuit includes Wima polypropylene and Nichicon Fine
Gold electrolytic capacitors. Right next to them are four very large Mundorf
M-Cap Supreme polypropylene capacitors. The same capacitors are used in the tube
output circuits. The latter employ the 6H30 super tubes', first used by BAT
and for some time imported exclusively by this American manufacturer. The
rectifier tube sits in a classic ceramic socket but the output tubes are mounted
in sockets from CMC, the same company whose beautiful RCA connectors can be seen
on Sigma's rear panel. According to Ayon, the I/V conversion circuit and the
gain stage are fully balanced, while the output is single ended. More expensive
DAC designs use a fully balanced topology throughout. However, the XLR output is
not just a gimmick. Gerhard has come up with a special tube circuit arrangement
which allows the use of a single ended topology with balanced output. The power supply uses a low-noise R-Core power transformer
with several secondary windings. Tube rectification is on the 6Z3 diode
manufactured in China. Separate power supplies and voltage regulators are used
for plate and filament supplies, logic and DAC circuits as well as the input and
output stages.
A Few Words From Ayon Audio We also had no idea that this was the beginning of a long digital journey for Ayon. The CD-1 became a big success around the world, with many great reviews and awards. This was the signal for Ayon to digital engineering and start in-house development for which we founded a kind of joint venture cooperation with Stream Unlimited in Vienna. We started developing our second generation of CD players, including the CD-07, CD-1s, and CD-2. We designed a new chassis, a new D/A converter, a new mechanism and output stage, the CD-1s had nothing to do anymore with the first generation CD-1. Then came the CD-5 and the Skylla, followed by the CD-07s, CD-1sc, CD-2s and CD-5s. In 2010 we introduced the S-3 network player, the first network player worldwide to feature a tube output stage, followed almost 2 years later by the S-5 reference network player and then the NW-T. After 6.5 years of production of our Skylla D/A converter it was time to renew and expand the lineup with the new Stealth and Stratos, the first tube based D/A converters with DSD playback. At the end of 2013 we launched the third and latest generation of our CD-Players: the CD-1sx and CD-3sx, the first tube based CD players worldwide with a DSD-enabled D/A converter on board. In mid-2014 we are pleased to introduce the smaller brother of the Stealth and Stratos, the Sigma DAC. The Sigma is a breakthrough for Ayon and unique in its price range as it is also equipped with a DSD DAC and SE 6H30 output stage. Our main goal has been to build a superb sounding tube DAC for
around half the price of our famous Stealth DAC. Gerhard Hirt
Sound Since Jaspers, the concept has been evolving and it is no
longer so clearly defined or "sharp." A boundary situation now also includes
experiences that change our point of view or our understanding of something,
turning inside out the construct of the world as we understand it. And they do
not necessarily need to be the basic existential experiences, like death. It may
be any other memorable experience, I think. It is not difficult to find such moments in our lives, filled
with auditions and listening to music. The first and foremost is what can be
called the "initiation" experience. It happens when, for the very first time, we
listen to the music played back in a way that unlocks something new in us,
opening up our eyes metaphorically speaking to the world of real music,
not just some noise with melody and beat. A wonderful aspect of the initiatory
experience is that it can be repeated, at an increasingly higher level, over our
whole lifetime. The reviewer is immune to such things. Daily listening to
music on constantly changing audio products in various configurations,
participating in music concerts and audio shows and meetings with friends kind
of immunizes us, like a vaccine. Given all that, when we eventually do have this
type of experience, it is always something. I may have mentioned it somewhere, but let me repeat it here:
I have recently heard twice the kind of sound that recalled my first-ever
experience of this type, which happened when I walked into a music store,
located in a seventeenth-century building at the Main Square in my home city of
Krakow, Poland. The audio system was absolutely classic for that time: a CD
player whose name I forget, a NAD 3020 amplifier and a pair of small monitors.
But its sound moved me so much that I set out to eagerly look for something that
would give at least half that "punch". Many years have since passed
and my expectations have obviously changed. The upside is a change of my audio
consciousness and sensibilities. The downside the price I now need to pay
for those dreams. My two recent boundary experiences have been the auditions of
the dCS Vivaldi digital system and the TechDAS Air Force One turntable. After
them, nothing has been the same. The Vivaldi costs insane money and sounds insanely good. Its
sound is my current reference. But it doesn't mean that nothing else
"sounds" good to me anymore. One of the advantages of the
"vaccination" I've mentioned earlier is the ability to evaluate audio
products regardless of the price range involved. That's why my recent auditions
of several excellent DACs bring nothing but fond memories and smile to my face.
Each one of them had that special something that touched my heart and made me
think that I could happily keep it. They were (in no particular order): the
Accuphase DC901, the Meitner MA-1, the Thrax Dionysos and the Ayon Audio Stratos.
The latter also comes with a great preamplifier on board, and has become a part
of the audio system that has been built over the years by Tomek, one of the
founders of the Krakow Sonic Society. When I bumped into Gerhard Hirt during the High End 2014 show
in Munich and after we gave each other a big hug, he showed me his two new
products: the long-anticipated production version of the Spheris III
preamplifier and a much more modest-looking box with a display screen on the
front panel. "The Sigma may be my least expensive D/A converter, but you don't
even realize how much it inherits from the Stratos that you have auditioned."
Gerhard is not the kind of person who gets easily excited over anything. He
works hard, does not sit still for a moment and wants to implement every new
upgrade as soon as it is ready, without looking at the cost. Other companies
often prefer not to change anything and keep selling a given model until they
replace it with something completely new. I have a feeling that while Gerhard is
an excellent businessman he does not calculate when it comes to the sound, but
simply follows his heart. Hence, I wasn't too much surprised that after hooking up the
Sigma to my system, the sound was not very different from what I'd heard with
the flagship Ayon DAC. I'm referring here to the sound on the coaxial input,
with the signal fed from my Ancient Audio Lektor Air V-edition (with Philips
CD-Pro2LF) used as a transport and the volume level set to "Max" in the Sigma.
This is an important provision to which I will return later. I have known digital components from Ayon Audio from the point
"zero," in other words from the company's very first CD player and first USB
input. They have been evolving incredibly fast and, in my personal opinion,
heading in a good direction. The thing that attracted me the most was the combination of
fleshiness and resolution. These sonic aspects used to be attributed to analog
recordings, with a special nod towards vinyl and now also towards DSD files
(reel to reel tape is a whole different story). Here, it benefited literally
each CD I auditioned. However, it was particularly striking when I listened to
the album "Billie Holiday" from 1952, remastered and released on SHM-CD in Japan
as part of the series "David Stone Martin 10 inch Collector's Selection". The
sound was amazing and maintained a kind of "internal concord",
characteristic of recordings before multi-track and multi-session era.
Holiday's vocals were big and strong. Her accompanying band with Oscar Peterson
and Ray Brown was perfectly audible. The same trick was repeated on Nina Simone's
album "Silk & Soul" from 1967. The vocalist was shown close to me; her voice
had a large volume and was very authentic. Both discs also feature tracks that
are much brighter, with more distant and brightened vocals. The Ayon showed them
nicely, although they were not so intimate. The more expensive DAC from the same
company was capable of something more: by going deeper into the individual
sounds it brought more music out of them. The Sigma was not as resolving and
selective. It did things its own way, making the lesser quality recordings sound
similar to each other and smoothing them out to the point where they are
listenable. It may also happen that we become fascinated with something
else, right from the very beginning. When I was playing Kraftwerk's bootleg "Live
on Radio Bremen" recorded in 1971, followed by Kenny Burrell's "Soul Call," I
sunk into my sofa, on which I sit during the auditions, feeling fully relaxed.
The Austrian DAC played both albums absolutely stress-free, bringing out the
same transcendent quality of such different music. Transcendence in this case
translated into calmness and suspension of disbelief. I could hear perfectly
well that they were just recordings, but only when I wanted to hear it and when
I paid attention to it. And it was not so easy to transition from holistic to
analytic perception as the Sigma tends to provoke the listener to turn off the
critical part of one's consciousness. When you get used to it and are willing to hear it, you will
notice that the sound is somewhat "made up." You will realize that it elicits a
certain desired response. The Sigma does it mostly by means of slightly boosted
upper bass and lower midrange. This always results in a closer foreground and
larger volume. These are good changes. They have usually been associated with
tube-based audio components, although the DAC under review is not a typical tube
design. Today it is no longer a clear-cut distinction, and in a blind test many
listeners would actually point to some solid state components as sounding
tube-like. It can also be easily noticed in Sigma's sonic signature. So why am I
talking about its great sound and what prevents me from pointing out this
coloration? To answer this question, I had to audition more albums and
audio systems. I am not sure if my answer will be satisfactory to everyone. It
is the only one I have, though, and I do not even look for another. In my
opinion, the coloration is deliberate and has been well thought out. It is not
to deceive anyone. On the contrary, it is an attempt to bring us even closer to
music. The "hidden hero" of this sound is resolution. I know, I've already
mentioned it. Except that now its role takes on a completely different meaning
and becomes crucial. I believe that over the years the high-end audio industry has
been developing in the wrong direction. The quest for neutrality at all costs
has been a curse. And equating low distortion with purity in a
"clinical" sense has been really stupid. In my experience, the
lower the distortion, the warmer the sound, the more "naturally velvety" and
softer. Many speakers with ceramic and diamond as well as some metal drivers are
a perfect example. The most notorious distortion we face in digital audio systems
is jitter. There are many types of jitter and we fight with them in various
ways. Often, minimizing one type results in increasing another one such is
life. The reduction of jitter and of the total harmonic distortion have one
thing in common: the lower they are, the more natural and denser the sound. And
the more it takes on the characteristics of "diversity in unity." It means that
there is more and more information that is increasingly better ordered. In the
end, the sound can no longer be called "detailed," even though it has
everything. And so it is with the sound of the Sigma. It is presented in one
"package", without being artificially segmented into separate
categories. It is up to us to decide if we want to focus on its individual
aspects. The tonal balance of the Sigma is shifted downwards and can be
called "warm", bearing in mind everything I have said above. The upper treble is
incredibly resonant and rich in nuances. The cymbals decay slightly faster,
which results in a sense of intimacy and closeness to the sound. The recording
venue's acoustics is denser and less differentiated, and the reverb added by the
sound engineer is shorter than on the Accuphase DC-901 paired with my Ancient
Audio Lektor. This is the price we pay for "presence." It is also worth paying
attention to the low bass control in your system and in your listening room. The
Sigma has a very deep low frequency extension, and the bass is energetic and
well differentiated. But it is not as punctual and tight as on the Stratos or
the Accuphase DC-901. It sounds more like the Meitner DAC or the Audio Research
Reference CD9. As the new entry-level model in the Ayon Audio DAC lineup, the
Sigma is not far from the flagship Stratos. The subtle differences I referred to
earlier can be identified, but they are not obtrusive. This is a fantastic DAC
that will not be out of place in the best audio systems I know. In most aspects,
apart from the soundstage depth and bass differentiation, it sounds better and
more convincing than my long-term reference Ancient Audio CD player. The above remarks are based on digital inputs using high-end
external CD transport. The file player bit resolution is reduced, regardless of
what kind of use of files. The USB input is very engaging and will give much joy
to all users who play music from their computers, or use digital music players
with a USB output, such as the Aurender. Tomek, who owns the Stratos, uses the
Aurender X100L and the pairing is perfect. Still, I think that a good CD release
played back on a quality CD player sounds more coherent and resolving. I know
that this opinion does not make me very popular, but I cannot help saying what I
really think. The only exception are DSD files. Too bad it's such a niche
format, because native DSD files sound insanely good calm, smooth and soft. The biggest difference between the two Ayon DACs we are
talking about is the sound from their USB input and the quality of their
built-in preamplifier. The Stratos' preamp is so good that adding to the system
the Polaris III, a two-piece flagship Ayonpreamplifier, brought only the kind of
benefits that I could easily do without. In the case of the Sigma, an external
preamplifier will improve the selectivity, resolution, liquidity and depth of
sound. This is quite a lot. Having said that, taken on its own merits the
built-in Sigma preamplifier is actually pretty good. It will not, however,
replace a dedicated specialized preamplifier.
Conclusion
Albums Used During Review Opus3 DSD Showcase2,
Opus3, source: Opus3, DSD64 + DSD128. SATRI Reference Recordings
Vol. 2, Bakoon Products, source: Bakoon Products, FLAC 24/192. Arturo Delmoni, The Songs
My Mother Taught Me, John Marks Records JMR One/JMR 1G, gold-CD
(1994). Billie Holiday, Billie
Holiday, Clef/UMG Recordings UCCV-9470, "David Stone Martin 10 inch
Collector's Selection", CD (1954/2013). Charlie Haden & Antonio Forcione, Heartplay,
Naim Label, 24/96 FLAC, source: NaimLabel. Daft Punk, Random Access
Memories, Columbia Records, FLAC 24/96 (2013). Dead Can Dance, Anastasis,
[PIAS] Entertainment Group, PIASR311CDX, "Special Edition Hardbound Box
Set", CD+USB drive 24/44.1 WAV (2012) Diana Krall, From This
Moment On, Verve, source: HDTracks FLAC 24/96 (2006/2011) J.S. Bach, Die Kunst Der
Fuge, Marcin Masecki (piano), Lado ABC C/13, CD (2012). Keith Jarrett, The K๖ln
Concert, ECM,source: HDTracks, FLAC 24/96 (1975/2011). Kenny Burrell, Soul Call,
Prestige/JVCJVCXR-0210-2, XRCD2 (1964/?). Kraftwerk, Live on Radio
Bremen, Philips 2561971, Bootleg, CD (2006). MayukoKamo, Primo,
Sony Music Japan SICC 30095, "Best Classic 100", Blu-spec CD2 (2008/2012). Miles Davis, Kind of Blue,
Columbia/Legacy/Sony Music Entertainment, source: HDTracks, "The Original Mono
Recordings", FLAC 24/192. Miles Davis, Tutu,
Warner Brothers Records/HDTracks, FLAC 24/96 (1986/2010). Modern Talking, The
Collection, E.M.S.S.A. Argentina/Sony Music Entertainment Hong Kong
88725439142, "Limited Edition No. 0420", K2HD CD (1994/2012). Nina Simone, Silk &
Soul, RCA/BMG UK & Ireland 2876596202, CD (1967/2004). Persy Grainger, Lincolnshire
Posy, Dallas Wind Symphony, Jerry Junkin (conductor), Reference
Recordings, HR-117, HRx, 24/176.4 WAV, DVD-R (2009). Stan Getz/Joao Gilberto, Getz/Gilberto,
Verve, source: HDTracks, FLAC 24/96 (1964/2009). Stan Getz/Joao Gilberto, Getz/Gilberto,
Verve/Lasting Impression Music LIM K2HD 036, K2HD Mastering, "24 Gold
Direct-from-Master Edition UDM", CD-R (1964/2009). The Handsome Family, Singing
Bones, Carrot TopSAKI036, CD (2003). The Joe Holland Quartet, Klipsch
Tape Reissues Vol. II, 1955, 57, DSD128. Yes, Close to the Edge,
Warner Music, FLAC 24/192, source: HDTracks (1972/2007).
Specifications
Company Information
United States Distributor Voice: (888) 593-8477
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