AYON STRATOS Reference tube DAC/PREAMP 32/192 DSD64/128

NZ$ 17,995.00 ea (incl. GST)
Ayon Audio

"The Bugatti of Audio" - TAS: The Absolute Sound magazine


Reviewers Comment:
"This is truy a world class DAC / Preamp that will breath new life and form the heart of any high-end system. Image reproduction is exceptionally three dimensional with the most subtle spatial energy suddenly revealed. It will, in Ayon tradition, provide a lifetime of consistent excellence".....

"Stratos is without a shadow of a doubt one of the best DACs I've ever heard. It makes music, and the best possible way",.........Thierry Nkaoua - Audiophile magazine

The Stratos is also prepared for computer playback and general DSD professional audio use. The quad differential gain stage is composed of 2 high performance tubes per channel. The Stratos DAC features a vastly overrated, high capacity power supply for the analog output stage with tube “bridge” rectification, choke coupling and two oversized power transformers. The sound is powerful with fantastic bass speed, extraordinary dynamic, airy, finely detailed and outstanding 3D holographic. 

The Stratos offers an uncompromising build and reference sound quality level in every aspect.

"STRATOS is without any doubt one of the best DACs I ever listened to. It makes Music, and in the best possible way. It is comfortable in any situation, from Rock dynamics, to Opera sweetness or Blues laments. With DSD, simply on USB, it takes advantage over SACD players that cost twice or 3 times more. With PCM, Stratos is very close to the wonderful Ayon S5 streamer. Again, it takes advantage over DAC that costs twice or 3 times more. And you get a full preamplifier with the DAC! A close integration between DAC and preamplifier seems to really become a design Must"...........Audiophile Magazine

Ayon Design

Ayon has established a new performance standard for digital products with high-gain “vacuum-tube output stage” in their class. The Ayon DACs and CD-Players are a remarkable union of innovative design concepts and refinements of existing technologies.

The benefits of our beautiful solid, rigid and non-resonant aluminium-anodized chassis are immediately audible compared with some sheet metal structures or poor thin aluminium chassis employed by most manufacturers. The 6H30 high-current tube remains the anchor for our super efficient analog “high-gain” output stage. (Shortest possible signal path – which is always the best)

Critical components are selected according to listening tests and technical performance without regard for cost.

Every Ayon DAC and CD-Player delivers the emotional power of music with a visceral impact, springy-deep bass, warm and fluid mid-range, high frequencies are never harsh or strident, and they have a natural grace – a glistening life-like presentation.

Image reproduction is exceptionally three dimensional with the most subtle spatial energy suddenly revealed. It will, in Ayon tradition, provide a lifetime of consistent excellence.





Full-featured Tube D/A converter and Preamp Class-A triode vacuum-tube output stage for single-ended & balanced operation

Signal Path 
We believe that the simplest circuits work best together with the shortest signal path. That is why our pre-amplifiers to date have used single-ended pure class-A circuitry. The shorter the signal path is, the less possibility of sonic degradation from various sources, including the wire itself. Even on the circuit boards, the copper traces are kept to a very minimum length. The completely redesigned circuit board provides a more straightforward and direct approach to the signal paths.

Logical sequenced soft-start power up for extended tube life
Warm up function
0dB negative feedback  (of any kind )
Ultra short signal path
Simplest direct circuit path for purest musical sound and high reliability
Low output impedance for driving long runs interconnect to an amplifier, and any tube or solid state power amp
No solid state devices in the analog tube output (signal path )
Minimal discrete wiring for optimum signal propagation
No followers or buffers in the signal path
High quality parts throughout
Fully hand assembled to insure the highest level of craftsmanship
Separate analog output stage for left and right channel
Analog inputs ( single-eded and fully balanced)
Upsampling and on/off switchable
All digital inputs
USB input (24/192 asynchronous  and DSD)

Power Supply
The power supplies have been further refined with new components and enhanced AC line noise filtration. Separate power transformer windings and filters provide total isolation between the input and output stage which makes this a pure power source and it is a critical attribute for a 6H30 output stage. We also use electrolytic capacitors with much larger storage capacity to make up for the loss in filtering when using resistors in lieu of inductors.
2 separate R-Core / Low noise – insulated power transformer for digital & analog

Tube rectification
Choke – filtered power supply and coupled with special film caps
Innovative power supply provides a high speed energy delivery on transients
Separate and isolated power supplies over each stage of amplification
Regulated DC filament supplies with soft start for tube
AC power line filter to avoid noise and hash from entering into the unit.
10 separate voltage regulators

The type of parts used therefore must have a synergistic relationship to the circuit they are placed in. It is this relationship of which type of part to use where, that ranks our products apart from the mass.

Selected, premium quality passive components used in all applications
High speed  & high quality audiophile grade coupling capacitors
High quality Teflon tube sockets with gold pins
Superior capacitors ( MKP 1% )
High quality – RCA & XLR jack
Gold-plated industrial grade PCB

Mechanical Construction
The high grade aluminum chassis impart a richer, more lustrous tonality with a cleaner back-ground and less hash and grain. All brushed anodized anti-vibration-resonance and non-magnetic chassis’s are fully hand assembled to insure the highest level of craftsmanship.

Front panel descriptions are engraved
AC phase polarity control indicator
The aluminium feet are resonance absorbing types
Chassis finish: black / chrome


Conversion rate:  32 bit PCM up to 192k - 64xDSD, 128xDSD
24/192 up-sampling
DAC configuration:  16 mono DACs to 2-stereo outs
Tube complement:  4x  6H30 tube output stage / 4x 6Z4 tube rectifier
Dual Electric-Analog-Switch Volume output comntrol
Dynamic range:  > 130dB
Output level @1 kHz / Rms:  0-12V
Output impedance  Single-Ended-RCA:  ~ 300 Ohms
Output impedance  Balanced-XLR:  ~ 300 Ohms
3x Line In
Digital Inputs 
PCM - USB-24/192, 1x S/PDIF, 1x BNC, 1x AES/EBU, 1x I2S, 1x Toslink
DSD - USB-DSD, 12S/DoP, 3x BNC for DSC (DSP-L, DSD-R,& WCK)
Analog input:  2 x RCA & 1 x XLR
Analog outputs:  RCA & XLR
1x Tape Out
S/N ratio: >120 dB
Frequency response:  20Hz - 20kHz  +/- 0.2dB
Total harmonic distortion @ 1kHz:  < 0.002%
Remote control:  Yes
Dimension: 480W x 420 D x 110H mm
Weight: 17 kg
Specifications subject to change without notice


Stratos is without a shadow of a doubt one of the best DACs I've ever heard. It makes music, and the best possible way,
Thierry Nkaoua - Audiophile magazine (French / English translation)

Review Summary: we are overwhelmed by the orchestra, his passion, his rage and pain. The tubes, capacitors, chips, cables, everything is forgotten when the symphony begins.

"STRATOS is without any doubt one of the best DAC I ever listened to. It makes Music, and in the best possible way. It is comfortable in any situation, from Rock dynamics, to Opera sweetness or Blues laments. With DSD, simply on USB, it takes advantage over SACD players that cost twice or 3 times more. With PCM, Stratos is very close to the wonderful Ayon S5 streamer. Again, it takes advantage over DAC that costs twice or 3 times more. And you get a full preamplifier with the DAC! A close integration between DAC and preamplifier seems to really become a design Must

You said "cloud music"?
What we call "Dematerialised Music", the Anglo-Saxons, more pragmatic, but perhaps less poetic, have called "Computer Audio.

However, to replace physical media, CD, which disappear (maybe) one day, never much "material" was necessary.

In addition to traditional amplifier and speakers, you need a computer to rip CD's, internet connection for shopping, a PS3 to rip SACD its a DAC or a network drive, or a network drive and DAC, a computer (silent if possible), or else a NAS software to decode tracks or UPNP server software to organise his nightclub, another or the same label for his albums with tags, a USB cable for direct connection computer-DAC, any USB / SPDIF interface then an additional SPDIF cable, ethernet cables and switches to network drives, hard drives to store his albums and others to save a tablet to control everything.
Not to mention a box of aspirin: to "dematerialise", one could imagine a more simple. Given this profusion of technologies and equipment, much of audiophiles hesitates, and as we understand!, To take the step of dematerialisation. Is this really the time to get rid of the CD player or SACD, and small cakes that nourish? cakes that while we often difficult to find in many furniture where they are arranged and everything perennial ranking is doomed when the discotheque grows.
Some caution is probably in order, for example, by making the hand and ear from the DAC access a CD player powered by a computer. Personally, tests on this type of configuration during the last two years have often random or incomprehensible results: heightened sensitivity to USB cable, for example, or significant deviations following software decoding employees, and results a little too far from what is obtained with the CD player itself.
Under these conditions, the acquisition of DCA seemed hardly appropriate. Depend on both the firm of Richmond, or the Cuppertino, and a USB cable with the protocols seemed neither established nor really effective, was hardly engaging.

The missing link

The key to paperless seems to revolve around a actually quite simple question:

DACs work very well for many years "in" CD decks, how, with what technologies and what materials feed from Flac files, Alac, AIF or DFS? In other words, what is the link which cooperate computer and DAC, which transmits the decoded audio stream on the computer to the DAC?

On one side of the PC or Mac with USB, Firewire, Ethernet, some cards with SPDIF or AES / EBU outputs, the other DAC with SPDIF or AES / EBU inputs.

Without going into the details of the reasons more or less good and disreputable that led to it is the USB has become the interface "up to date" on which many PC-DAC connections were built.
In the protocol USB Audio Class 1 is the clock of the computer, not really "consistent" with upmarket DAC, which controls the audio stream to the DAC.
With the term "USB 2", still some confusion. ports 2 USB allow greater throughput than USB 1, thereby exceeding the limit of 24/96 USB 1, but that does not mean that the audio protocol used is different or better ...
It then appeared DAC interfaces and USB / SPDIF asynchronous based on USB 2 in terms of throughput, but everyone from the proprietary protocol to pass the audio stream to the USB pipe.
This has been in many cases (but not always) an improvement over the protocol USB Audio Class 1. But as nobody knew and will never know what there is in these proprietary protocols ... Still that it is with this kind of asynchronous USB 2 owner I knew disappointments and misunderstandings mentioned above.
May 31, 2006 was nevertheless output a protocol standard USB Audio Class 2, available on the website of the e USB consortium . The standard is distributed as 3 documents totalling 187 pages. But as always, it is not because a standard lot enacted, manufacturers have invested in developments owners generally want to recoup their investments before making other.
The first advantage of USB Audio Class 2, this is simply to be a standard! This allows players to control their technological development and buyers know where they put their money.
USB Audio Class 2 is available natively on Apple OSX (and Linux) without additional drivers since mid 2010. For Windows, 7 years after the release of the standard, this is not always the case.
The second advantage is technological and undoubtedly audiophile DAC is a side which controls the transmission of the audio stream of the computer clock, and filling / emptying a buffer containing the audio stream as close to the DAC.
This can be summarised brutally, albeit a little absuivement, saying that USB Audio Class 2, the DAC takes control of the computer. The rest of the advantages (and constraints), it is in the 187 pages of the standard.
Of chip designers (like that provided XMOS USB interface for DAC Ayon Stratos) produce shelf components, interfacing with I2S a receiver chip USB Audio Class 2 to DAC cards.
7 years after the release of this standard, there is not yet finally been "massive" adoption of this standard. Mention may be made naturally Ayon with his two new DAC Stratos and Stealth, but also TotalDAC or Antelope. But others prefer to continue to use their proprietary protocols as Esoteric, DCS or Audio Research. Only tracks will naturally make sense of things.

Do not let the computer do the audio?

It seems to some, I admit part, the computer may not be the "ideal" device to be integrated with a High End HiFi system.

The computer has a very basic diet, its connectivity is not an exemplary quality of workmanship, and its operating system must manage graphics card, keyboard, screen, etc.; in a myriad of processes.
If  "everything that's not designed for this computer"  was in fact closer to the DAC IN HiFi equipment and dedicated chips and not an operating system généralsite, things could / should be a priori best and simpler. View may be simplistic.
Certainly, it is then necessary audio software engineers and engineers work hand in hand (which is undoubtedly a challenge in itself), but Linn, Upper Range, with streamers (network drives) or Sonos with more modest but very robust products, showed a path that seemed to be good.
For a little over a year, we see the arrival of network drives in the catalog of many manufacturers, all segments of the Consumer the Most High Range. For example (non-exhaustive list of course): Atoll, Audio Research, Ayon, Cambridge, Denon, Marrantz, NAD, Naim, Pioneer, Rotel, Simple Audio, Yamaha. But among the great names of DAC, some still do not offer, or DCS Esoteric example.
An early move towards this integrated architecture therefore seemed to begin to emerge. In this architecture, the computer no longer has any audio function, merely to send files to the device: decoding transport to the DAC and DAC are integrated into the network drive, which ultimately mirrors the architecture of a good old CD player.
I followed this movement by not crossing the dematerialisation late 2012 with the acquisition of a Ayon S5 network drive, then Lumin a network drive, it can treat the DSD. Both giving me satisfaction far beyond all my old CD players and SACD. The test bench on 6 moons of  Ayon S5  shows "best source PCM ever heard" and that of  Lumin  on Audiophile Magazine is of the same ilk as regards the DSD.
The earliest appearance of these two products seemed to sound the tocsin more or less long term (presumably long) for CD and SACD moribund two network Upscale readers were at least as good as or better than the best plates CD and SACD. The variation in the ranges of manufacturers should be able to engage.

Ayon against the foot

That's when we decided to take qu'Ayon against the foot. After having designed and produced a stunning network drive, Ayon makes his catalog two new DAC, called Stealth and Stratos. Mass between Computer Audio and Network drives would not be called?

The new DAC accept DSD. This is against a second floor, when we know that Gerhard Hirt, owner of Ayon and supporter of DSD in its creation, expresses doubts about the commercial durability of this format, too many studios merely converting their decision PCM to DSD, which is of little interest.
When Gerhard Hirt proposed DAC Stratos Audiophile Magazine for Test Bench, it is with great anticipation and curiosity that I expected delivery: would I have to revise my position on the Computer Audio? Is it possible to reach the level of resitution one of the best existing network drives with Audio Computer architecture, computer resuming service to decode tracks?
This test bench then follow the following three red son:
How is the Stratos DSD to PCM and USB?
The USB 2 Audio Does it solve the problems usually encountered in USB and Computer Audio has he made ​​significant progress? 
How is PCM DAC Admiral Stratos compared to S5 Player Network Admiral Ayon
DAC Stratos (like his little brother Stealth) consists of integrating a DAC and a preamp tubes. Ayon has also changed the corporate name to "DAC-Pre".
Three elements are often cited as key in the operation of a DAC:
The output stage
The conversion stage
As we will see in the description that follows, Ayon pushed far the design of each of these parts, and component selection.

Gerhard Hirt provided additional information to what is found on the Ayon website:

Preamp output stage of the Stratos is the same as the streamer S5.
feeding Stratos is a little "below" that of S5. Although the case of Stratos took a few cm deeper compared to S5, S5 external power could not stay in the case of Stratos. There is then a choice of positioning and market segmentation.
DAC chips, Sabre ESS9018 were chosen after several disappointing attempts with chips from other manufacturers.
In fact, the regret is that Gerhard Hirt BB 1704k chips that fit the previous DAC SKYLLA II, the former range of CD players and S5 are not DSD compatible. He enjoys both the chip he bought all the stock available there a few years ago.


Stratos comes in a double carton. Stratos and the remote control are wrapped in black fabric cover.
A user manual in English, and a CD containing the necessary USB drivers for Windows 7 and 8 complement the packaging (Mac OSX natively handles the USB 2 Audio and requires no drivers).
In front façade, a volume knob and another to select the entries around a screen giving some information operation:
Volume level
Selected digital input
Filter 1 or 2
The rear panel offers a more than full connectivity.
At both ends, are the analog outputs, RCA and XLR. 
Right, four configuration switches:
Connecting to an integrated amplifier or power
RCA, XLR or RCA and XLR output simultaneous
Output level Low or High
Acoustic phase inversion
In the next section surrounded by a white line, moving to the left is all digital inputs:
USB 2 Audio, ready to support USB 3 (PCM and DSD)
I2S RJ45 (PCM)
I2S RJ45 (optional DSD DoP)
Toslink SPDIF (PCM)
3 BNC (R, L, WorldClock DSD)
To the left of the entrance area, an indicator identifies the AC phase, as all Ayon products. A handy device.
In the last white box, analog inputs and outputs of the integrated preamp:
an XLR input
two RCA inputs
an output for connecting headphones or a subwoofer.
The remote allows you to control the amps, preamps, DAC and CD players of the brand.
For Stratos, useful buttons are for volume, balance, upsampling, mute, and input filter.
Two types of filters are available, the second being advertised as more "stiff". Sabre ESS9018 chips allow programming of these filters.
As a kind of protest Credo for all amps, preamps and sources Ayon highlights some characteristics of the output stage, such as:
0 feedback
Audio path ultra-short and simple as possible
Low output impedance
No buffer or follower on audio path

Configurations Listening:

Given the wealth of available connections, several configurations were naturally used their discretion will be given over the listening found later account. It has used the USB input PCM and DSD, SPDIF PCM since S5 used network drive (configuration probably close to the use of drive Ayon NWT), the BNC input from the PCM Lumin on a network drive.
Alas, it was not possible to test the 3 BNC DSD announced by Gerhard Hirt as "superior" to the USB inputs. For USB, all tracks have been made with the new cable Tellurium Q Black Diamond. A comparison with a "computer" Monster Cable High Speed ​​will be given at the end of Test Bench.
Stratos has always been utilise in output level "low" as recommended by Ayon for the type of amp used.
It seems important to note that the Stratos has always been used "on its own preamp." When comparisons were made with the Lumin, it has also benefited from the preamp Stratos.

Impressions "out of the box"

After quickly connected the Stratos Mac Mini with the USB cable Tellurium Q Black Diamond, small satisfaction, Mac immediately recognized the XMOS USB Audio 2 Stratos interface, JRiver was then configured in 3 clicks to get out of this interface to send "DSD bitstream DoP" for DSD tracks.
IPad in hand, Jremote application, choose the player (player JRiver) choice of the album, click on the track, the sound works! Second small satisfaction (those who have struggled with Computer Audio readily understand these childish satisfactions).
Program, one of my favorite albums DSD, the 7th Symphony by Beethoven Ivan Fischer Channel Classics in an absolute highlight of interpretation and miking. Second movement, Allegretto.
I find instantly the "signature" of my beloved Ayon S5, the image is wide and deep, sound clips between winds and strings are well spaced, stamps winds ring true, the presence of the musicians is realistic hair the arms are there.
I pursue these first impressions by listening to the fourth movement of the same album. Allegro con brio. You look up to the "shots" copper, basically, that punctuate the massive orchestral movement and Onsite this Allegro con brio. But when the solo flute is telling us naif theme of this movement, the difference in volume and dynamics seems totally natural and no impulsive movement toward the remote would be taken to increase the sound.
Tubes with non-functioning, a simple connection that works the first time, I am very far from my previous experiences of "Computer Audio", with Music and Emotions from the first listen.
But to make plays in the best conditions, it takes me fifty hours required for the breaking-tubes 6:30 (culminating means very easily).
Tic Tac, 50 hours of breaking-tubes pass.

The tracks

First impressions are confirmed throughout the plays, whatever the style of music. 
What strikes first, just like the S5 is the breadth and depth of the soundstage.
When Gerhard Hirt speaks holographic scene, one can think of an expression of marketing. And not at all! This 3-dimensional perception of music is very real, and also present on the Stratos on the S5.
Undoubtedly, the quality of "holographic" scene also depends on the amplifier, speakers and listening room. But "other fixed system", I heard more often than I would have liked, complete loss scene is by changing DAC or by changing decoding system used before the DAC, computers , or audio servers.
Through all the albums, no systematic or special colouring. Each album in PCM and DSD retains its personality. No standardisation of listening. Fluidity and naturalness are also waiting for you. The emotion and music "pass" without question.
What surprises me "really" is that all these features, 3D scene, absence of colour, fluidity and naturalness are to go "despite" the USB connection, including DSD. My previous experiences with asynchronous USB 2 (owner, not USB Audio Class 2) systematically leads to staining in acute and / or narrowing of the stage and / or flow.
So USB Audio Class 2 implemented with care, coupled with what seems an excellent USB cable, a DAC with a very neat and integrated with a fabulous power output stage achieves a quality that I had never yet heard with a "computer decoder tracks."
Much to say right now, it was not easy for me to conduct "analytical" plays this Stratos.
Music and Emotions are so present that must whip his brain to get him to listen to "bat" mode as the saying goes, and not to indulge in simply listening to music. So it took time, and many tracks "return" between the material to be something else to write that "WOW, what DAC".
Live in New York with Bruce Springsteen (DSD), the shouts and whistles from the crowd are accurate remaining distant. My streamer Lumin already gives excellent results in DSD on my system. In comparison, it also benefits the preamp Stratos (XLR connection). But it must yet bow on this album before the Stratos. It produces a lot more "en bloc" and further. The accuracy of Stratos as related to its power to its competition floor conversion makes the difference. The crowd and cries seem more natural with the Stratos, without turning to the formicary. In "The River" instruments are also more clearly placed on stage with Stratos. The voice of the Boss is better focused.
The legendary Kind of Blue remastered in DSD DSD my two competitors are at par, impossible to decide blindly. The differences are completely irrelevant. Really straining his ears, there is quite a few differences in tonal balance, but nothing allows me to prefer one to the other. The type of miking, and his age, full battery left, full right piano, trumpet centred, is probably not capable of clearly differentiating DAC that level.
With Hiromi Another Mind (DSD), the frenzy of Dancando No Paraiso is more impactful on the Stratos on the Lumin (volumes are controlled by a small portable sound level meter). The cymbals are made even more finely on the Stratos.
But I also have this album on CD. A comparison with the S5 PCM is therefore required. It takes this much time to strain to understand the differences. If the differences with the Lumin jumped ears with Bruce Springsteen, the ones with the S5 are more subtle. The sequence begins to 2mn12, pulsed field led by battery-cymbal is a bit better drawn on the S5 on the Stratos. The bass punctuates this sequence is more focused, less floating on the S5. The differences are indeed very small, but they do exist.
I take this album to try the S5 and Lumin network drive (PCM) of Stratos. And I am almost on my hunger reviewer! Everything fits in a pocket handkerchief. Lumin in the drive network Stratos indiscernible USB. As for the S5 networked drive, it can partially erase the already minimal differences between S5 and Stratos. The improvement is mainly the bass on this track, but also on other comparisons of this type (Enter Sandman, Metallica).
With the dramatic Adam Fischer version of the Mozart 25th Symphony, 16/44, once again the illustration that the sound is paramount, before or HD format. The readability of this squeaky symphony under the baton of Adam Fischer is quite amazing with the Stratos. Any sound alchemy of this symphony pass the test without flinching. Everything is audible, according to layout plans, flawless, but while maintaining fluiditié of the overall movement. Stamps winds, horns, oboes and bassoons are fully restored, the dynamics of horns that emphasise the whole first movement is particularly involved; punctuation oboe-bassoon is clear without take over the underlying sentences. Attacks bows on bass strings squeak like Adam Fischer has no doubt desired.
On this album, we are overwhelmed by the orchestra, his passion, his rage and pain. The tubes, capacitors, chips, cables, everything is forgotten when the symphony begins.


Stratos is without a shadow of a doubt one of the best DACs I've ever heard. It makes music, and the best possible way, it never tires, and also feels comfortable in the dynamics of the Rock as the sweetness of the Opera or the lament of Blues.
DSD, USB and simply, it takes a good step ahead of many decks SACD whose price will double to triple that of Stratos. 
PCM, it reaches the performance and musicality of S5 network drive ... a hair close. Again, competition is at prices ranging from double to triple.
We must not forget that the Stratos has a real preamp tubes 6:30, with an XLR input and two RCA inputs, usable for other sources.
Extensive integration preamp-DAC really seems to be a must in the design of DAC, and we better understand the new name "DAC-Pre" chosen by Ayon for its DAC.
Even if the chip is only one of many elements that contribute to the final quality of a DAC, one might have feared that the passage of the beloved smart Bur-Brown 1704k Gehard of Hirt another chip can lead certain technological difficulties and reduced musicality or a narrowing of the magnificent scene of S5, the CD player or DAC CD5S Skylla II. There is nothing. Sabre selected chip is completely forgotten, also like the rest of all other components handpicked.
Whether in Computer Audio DAC with the Stratos, or network drive with the S5, Ayon has clearly raised two major milestones on the two channels of dematerialisation, and pathways that are completely open.
 .........Thierry Nkaoua -  August 2013