⌈ DIGITAL AUDIO SYSTEMS is an Austrian company founded in 2014 by ALEXEJ C. OGOREK. It offers audio file players, Model 2, Model 3, Model 4 and amplifier MPA. These are devices aimed at playing files from a built-in hard drive, characterized by a unique design. We test its top-of-the-line Model 3 in its latest version. ⌋

E HAVE HEARD THE STORY HUNDREDS OF TIMES and we will hear a hundred more. DIGITAL AUDIO SYSTEMS was born out of a passion for music and the frustration of not being able to play it the way the designer expected. In this case, it was about playing digital audio files.

Alexej C. Ogorek, its founder, studied economics and mathematics at the London School of Economics and Political Science, and at the University of Cambridge. His background is therefore not in electronics. Instead, he is associated with music. As he writes, he founded the company in 2014, and it was the result of a search for a digital, high-end audio system.

At the time, Alexej had a large collection of vinyl records, which were his passion and pride. As his turntable was slowly running out of service, he decided to digitize his vinyl collection, and store it in files. He couldn't, however, find a device that would guarantee the faithful sound of the original vinyl. After, as we read in the materials sent us, a long search, he finally found devices, but professional ones, that met his recording requirements. Still, the problem of files playback remained.

For example, one set of records he wanted to rip was Joseph Haydn's early symphonies with the Philharmonia Hungarica conducted by Antal Dorati, recorded by Decca in the early 1970s. Nothing special, he says, but characterized by delicate tonal colours and a airy atmosphere that he found difficult to reproduce faithfully from digital medium with the best equipment then available. So he decided to design and make his own file player, based on the experience he gained while searching for equipment to digitize his vinyl records.

His reference point was the sound of LPs and "master" tapes played from a good mastering tape recorder. He set two goals for himself, concerning the sound and the user interface:

- Sound: the file player should sound natural and warm, capturing the timbres and ambience of the best analog playback equipment.
- User interface: the device should bring some of the features familiar from interacting with real records, such as LP album covers, so that users can enjoy images and lyrics while listening to music. In other words, he says, "the goal was to convey the atmosphere and vivid realism of high-end analog equipment in the digital domain and combine this with the convenience of managing digital files." Thus Digital Audio Systems was born.

▌ HD-Player Model 3

The HD-PLAYER MODEL 3, which we are testing, is the most technically advanced device from this company. In terms of usability, it differs somewhat from most devices available on the market, as its main task is to play files stored on the internal HDD. Which is understandable - after all, the designer was concerned with the best possible playback of digital copies of his LPs.

However, this narrows the functionality of the player. It turns out that we can't play files from NAS drives, but only from drives plugged into one of the two USB inputs. In addition, the proprietary software application allows for playback of streaming services, although MQA streams are decoded only to the first unfold. The designer writes about MQA extensively in a relevant document available on his website. To put it mildly, he is not in favour of this codec. Which has just lost its raison d'être, since Tidal, the only service offering hi-res MQA files, is phasing it out, introducing hi-res FLAC files in its place.

The HD-Player Model 3 is thus a device that is both an audio player and server. These names appear in parallel in its description, and that's because the device can play music from both streaming services and its built-in memory. The device plays lossless files such as WAV, FLAC, AIFF, APE, WavPack and DSD files (dff and dsf). It also works with a range of lossy files, such as Ogg Vorbis, Opus, MP2, MP3, MP4/AAC, ALAC, MOD, Musepack. The device supports PCM files up to 32 bits and 384 kHz, and DSD files up to DSD128, with DCD files converted to PCM 24/176.4 before conversion.

I started with abbreviations and numbers, but much more important, for me, turned out to be how the device was designed. For its appearance is phenomenal and it was because of it that I longed to listen to the device, even before I had read about it and appreciated the philosophy behind it. Let me say this: if Nagra made top-of-the-line file players for home use, they would probably look like the Model 3. Moreover, if Studer or ReVox made file players, they would look exactly the same. The Model 3 HD-Player is shamelessly "taken out" of a 1970s recording studio and welded into a high-end 21st century system.

Its front panel contains a great-looking display, on which we can find the album cover, track listing, title, time and file data, but also a smaller one, divided into two fields, showing analog VU-meters, i.e. indicators telling us about the output voltage. They have a "red" area, above 0 dB, but in digital devices the signal should never be so strong that the VU-meter arrow is there; if this happens, it means that the signal is digitally overdriven. In the tested player, however, the output voltage is measured, and we can select the range in which the measurement is made.

The device is controlled from a special app, designed on behalf of DAS, available for all mobile devices like Apple (iOS), Google (Chrome) or Microsoft (Windows). It looks great. The tablet connects to the player (that's what I'll call it) via a direct Wi-Fi connection. But we can also control the Model 3 via buttons on the front panel, just like a CD player or - this is probably a better comparison - a cassette or reel-to-reel tape recorder. It really works, and I did most of my listening using this option. It's a shame, then, that there is no remote control.

⸜ TECHNOLOGY - The mechanics in the tested player are stunning. Bolted to the aluminum chassis, supporting it, are steel plates and more plates, but aluminum ones. Running horizontally through the center is an aluminum plate dividing the two sections: analog (on top) and digital (underneath); this is how the so-called "clean" and "dirty" sections are separated from each other; the role of the former is played here by analog circuits, and the latter by digital circuits, generating tons of high-frequency interference (noise).

The player has a modular design and is based on a computer motherboard and Linux-based OS. Although we can play on it all PCM files up to 32 bits and 384 kHz, and DSD files up to DSD128, DSD files will be converted to PCM 24/176.4, because the basic idea was to reach for a discrete D/A converter of R-2R type, i.e. based on network of switched resistors. Such a circuit does not require oversampling circuits and digital filters, thus, by giving a pure pulse, without "ringing" before and after it. And this is the main reason for the "cold" and "technical" sound of some digital devices.

The internal media storage has a standard capacity of 4TB, but this can be expanded up to 12TB if desired. The unit has a dual-mono, balanced design. The signal is output via two types of connections: balanced XLR or unbalanced RCA. The former offer 4 V and the latter 2 V of maximum voltage. All the sockets on this player, including USB and ethernet, are from Swiss Neutrik and are professional versions - very good indeed.

The HD-Player Model 3 is a beautiful device with a well-thought-out design. But let's remember that its main purpose is to play files stored locally, and only then from streaming. It connects to the Internet via ethernet cable - or Wi-Fi.

▌ SOUND

⸜ HOW WE LISTENED • The HD-Player Model 3 stood on the top carbon shelf of the Finite Elemente Pagode Edition Mk II rack on its feet. The manufacturer says they are made of three layers of damping materials. Its sound was compared to the AYON AUDIO CD-35 HF EDITION SACD player and the LUMIN T3 file player.

With the router, the player was connected via my system, consisting of a SILENT ANGEL N16 LPS dual LAN switch, with its two modules in series, powered by a TIGLON TPL-2000A cable and via a TIGLON TPL-2000L LAN cable; more on this → HERE (PL); the router was powered by a JCAT Optimo 3 Duo power supply.

» RECORDINGS USED IN THE TEST ⸜ selection<

⸜ ART PEPPER, …the way it was!, Contemporary Records/Mobile Fidelity Audio Lab UDSACD 2034, DSD – rip z SACD (1972/2008).
⸜ ARNE DOMNÉRUS, Jazz At The Pawnshop, Proprius PRSACD 7778, WAV 24/174,6, rip z SACD (1976/2005).
⸜ DIRE STRAITS, Brothers in Arms, Vertigo/Mobile Fidelity Labs UDSACD 2099, „Original Master Recording, Special Limited Edition ⸜ No. 1808”, rip z SACD/CD (1985/2013).
⸜ LED ZEPPELIN, Led Zeppelin (I), Atlantic/Warner Music 8122796439, „Super Deluxe Box Set”, FLAC 24/96 (1961/2014).
⸜ ALEXIS COLE, A Kiss in The Dark, Chesky Records, Master Files WAV 24/192 (2014).
⸜ PRIYA DARSHINI, Periphery, Chesky Records JD450, Master Files WAV 24/192 (2020).
⸜ DEAD CAN DANCE, Anastasis, [PIAS] Entertainment Group PIASR311CDX, „Special Edition Hardbound Box Set”, CD+USB drive 24/44,1 WAV (2012).
⸜ THOMAS KESSLER, Close to Silence, Hypersensitive Recs. LC 91631, WAV 24/96 Studio Master (2022).

THE STEREOPHONY CAN BE QUITE A COURIOUS THING. When we listen to Stockowski's first, still experimental, recordings from the 1930s, or even when we reach for the first ever stereophonic LP by Audio Fidelity (1957), we hear a superbly composed, dense sonic panorama. The kind we know from good, contemporary recordings. Classical music followed this pattern, but jazz, pop, and later rock stepped in, shattering this illusion and moving some instruments to the left channel, some to the right, leaving the center empty.

The reasons for this are twofold, because on the one hand it is the limitations of the equipment, but on the other hand it is the inability of sound engineers to imagine what it should look like. This includes such fantastic specialists as Rudy Van Gelder and Roy DuNann. And just listening to the latter's recordings from the ART PEPPER’S ...the way it was!, released in 2008 by Mobile Fidelity Audio Lab on SACD, I heard something that later accompanied me in my test of the HD-Player Model 3 until the end of the listening sessions: fullness and warmth.

The Austrian player showed instruments and space in a significantly different way than my SACD player, and it was closer to Lumin T3 in this regard, and even more like a high-end turntable to me. The point is that the Model 3 densifies events and brings them closer to us. It has a stronger low midrange, and thus a less pronounced high range. Instruments were therefore closer to me and filled more space. This, for file players, is an absolute rarity, as their designers try to bring out as much detail as possible, which would prove the superiority of this medium over physical media.

In the case of the HD-Player, something else can be heard: an effort to make the sound as close as possible to that of a high-end turntable. But rather a turntable from SME, Linn and Rega than large and heavy uncoupled turntables. I got a similar impression listening to ARNE DOMNÉRUS's Jazz At The Pawnshop recordings, ripped from the SACD version released by the original publisher, the Swedish label Proprius.

The band crowded onto the small stage of the Pawnshop club played with the player sounded more like in a studio than on stage. And that's because all the sounds were fuller and had a low set balance. The space between them, perfectly captured by Gert Palmcrantz, was compressed between the more powerful sound sources (more → HERE). It was an excellent reproduction, but one that also had an agenda. And that agenda, it seems to me, is to provide maximum comfort when listening to any music from any file.

Because what I'm talking about can be heard both with DSD and PCM files, with jazz, classical and rock. When Knopfler sings "Why worry..." in the song of the same title, his vocals are warm and rich with the tested player, quite close to the line connecting the speakers. The same song played back from the SACD was shown more clearly, even a bit closer and with a wider panorama. It was a completely different playing, with more information.

At the same time, it was not the case that listening to the same recordings on the player I was missing anything. This is one of the paradoxes of audio. Every playback is the sum of compromises, and within those compromises you can change one or the other element and still remain at the same quality level. And the latter, in the case of the Model 3, is exceptionally high, it's a real high-end, what;s more, with a "human face", so to speak. That is, oriented to the user and to his/her connection with the music, and not necessarily informing exactly about the technical side of the recording.

It is a device that introduces us into its world. It constructs a deep soundstage in front of us with its own "air". These are not instruments thrown into our space, but a completely different dimension. When Dazed and Confused from LED ZEPPELIN's debut album, as prepared in 2014 by Robert Plant, begins, the player momentarily unfolds before us something like a dark, dense fabric and throws the individual sounds on it. We literally "feel" its thickness under our fingers.

And that's because the Model 3 is saturating the sound with low amplitude information, but not developing it into what we know as "detail" or "subtleties." At first, especially when compared to SACD discs played from a reference player, it seems that this warm, low-amplitude presentation is associated with the absence of some of the sound. This is not the case, this is absolutely not the case. This impression is built by the tone shaping I mentioned, not by the low resolution. It is enough to compare it with another player to see that there is something going on here that we know from vinyl. That is: rounding off the attack, but showing plenty of information in the process.

Only that we perceive them not as "details" or "subtleties". In fact, we can't hear them. For the presentation is dominated by a smooth, even silky panorama with instruments having a density and compactness that is usually lacking in recordings listened to from files. And related to this is the unique way in which the tested device presents the dynamics of the tracks. At first glance, it is sedated. It's rather warm playing, so we don't pay attention to it. Until something surprises us. But not a bright, sudden impact, but a jump of energy of the greater part of the band. It's not a punctuated hit, but more of a "push" kind of thing.

Also, the space offered by the Austrian player has a distinct shape, so to speak. As I said with the first two discs, the device clearly prefers direct sounds, large bodies. They fill the space between the speakers more strongly than from reference players. And this results in an image with less "air" between them. Even Chesky Records recordings, made mainly with Neumann KU-100 binaural microphones mounted on an "artificial head," are more similar in creating space to classic multi-microphone recordings.

What remains, of course, is the extraordinary feeling of immediacy and lack of constraint - this is what the techniques chosen by the Chesky brothers serve. Both ALEXIS COLE from A Kiss In The Dark and PRIYA DARSHINI from Periphery were thus closer to me than from CDs and CD-Rs of the same material, respectively, and their bodies were also fuller, denser, and thus less ethereal. Which worked out well for them.

▌ Summary

The HD-PLAYER MODEL 3 from Digital Audio Systems is a beautifully built device. Beautiful also in the sense that it is honest. The point is that everything about it is refined and well thought out. Similarly, by the way, in its sound. The latter realizes the intention of the designer, who did not try to render it in the most neutral way possible, because with files this strategy usually fails. Instead, he tried to make the recordings sound as natural, even physiological, as possible.

That's why the presentation is big, warm and round. Instruments and vocals have high energy and clear masses. The space between them, along with the micro-dynamics, are masked here by this very, tangible "presence." Which doesn't actually happen with file players. And if it does, it's at a much lower resolution than here. This is an exceptional device that you can listen to for hours without fatigue, searching for new recordings and albums.

▌ DESIGN

AS I HAVE SAID, MAYBE MORE THAN ONES, the HD-Player Model 3 is a very nice, very solidly built unit. Its chassis is assembled from aluminum boards, supported in the corners by angle brackets. It is reinforced by a horizontal baffle running through the center, also made of aluminum, separating the digital section, i.e. the file transport, from the "analog" section, i.e. the DAC, as well as the linear power supply. Additional bracing is provided by metal, but already made of stainless steel, screens in which the power supply and SSD are enclosed.

The Player is a modular design and is based on off-the-shelf components, selected, programmed and interconnected in a manner chosen by Alexej C. Ogorek. Its base is a motherboard running the Linux operating system. That's where the file player and control software and user interface are loaded. Along with it, from underneath, there is also a Wi-Fi receiver, it's TP Link "dongle", used to communicate the player with the control application, as well as two display control boards - these are also ready-made circuits. There is also a small switching power supply, but only for the displays. The control system and user interface are the result of two years of work by the designer. It is stored on a separate SSD.

From the motherboard, the signal is sent via a USB cable to a D2D converter board. From there we go either to the RCA and AES/EBU digital outputs, or to the DAC boards. We find information on the board that this is its third (Mk III) version. Four Transient DAC Two modules per channel are mounted on each board. Their total output voltage is high enough that there was no need for further stages, i.e. an I/U converter or output buffer - from the boards the signal goes directly to the output jacks. In the previous version, the DAC was supplied by Metrum Acoustics, and the D2D board by M2Tech. All modules are galvanically separated from each other.

Alexej C. Ogorek, instead of reaching for integrated D/A circuits, in which not much can be changed, he used discrete R-2R converters, in which the resistors are switched by transistors. As a result, the signal is not oversampled and there are no digital filters at the output. A simple analog filter operating above 70 kHz was sufficient there. ●.

▌ Technical data (according to the manufacturer)

• Maximum output voltage: RCA: 2 Vrms, XLR: 4 Vrms
• Output impedance: RCA: 100 Ω, XLR: 200 Ω
• Frequency response: from 1 Hz (0 dB) to half the sampling frequency (-3 dB)
• Distortion: <0.006% THD
• Signal-to-noise ratio: -125 dB for 16 bits, -135 dB for 24 bits
• Signal rise rate: 35 V/mS
• Dimensions (W x H x D): 430 x 140 x 360 mm
• Weight: approx. 20 kg

THIS TEST HAS BEEN DESIGNED ACCORDING TO THE GUIDELINES adopted by the Association of International Audiophile Publications, an international audio press association concerned with ethical and professional standards in our industry, of which HIGH FIDELITY is a founding member. More about the association and its constituent titles → HERE.

→ www.AIAP-online.org