| WORLD PREMIERE |

⌈ MuzgAUDIO is a Polish company, based in Rzeszów, founded in 2019 by an engineer KONRAD SIEMIENTKOWSKI for one purpose: designing and manufacturing audio components. We are testing its reference product in a semiconductor version, the DAC-01S digital-to-analog converter. This is its WORLD PREMIERE review. ⌋

OOKING AT THE CONTEMPORARY AUDIO SCENE, it is not difficult to notice that it is dominated by several parallel trends. The most spectacular is the presence of a vinyl record and the related retro solutions. This theme is quite "clickable" and looks nice on TV and in social media. And it’s a very good direction.

At the same time, however, we are dealing with a digital revolution, one could say: a revolution 3.0, after the introduction of CDs to the market, and then after the introduction of digital mp3 files. While vinyl is a thing of the past, regardless of its advantages as a music medium, it is part of what SIMON REYNOLDS in his book on pop culture called a retromania, digital is still synonymous with modernity and the future. This was the case in 1982, when Sony and Philips advertised their groundbreaking invention, the Compact Disc, and this is also the case today, in the age of music files and streaming services.

The revolution in question has already been going on - in terms of the consumer market - for exactly forty years. So is it still a revolution? Or maybe we dealt with a revolution at the very beginning, starting from the late 1960s, when the first prototypes of digital tape recorders for sound recording were developed, until the inauguration of the CD format? Maybe what is happening now is just benefiting from those breakthroughs?. It is clear that the latest solutions are getting better and more refined, but maybe they are nothing else but an evolution of the solutions from the past - maybe that’s the truth?

Wikipedia divides the periods related to the "digital revolution", but not in audio, but in general, in a way that would confirm these intuitive guesses, distinguishing the years 1969-1989 as the time of "the invention of the Internet and rise of home computers" (Digital Revolution, en.WIKIPEDIA.org; accessed on 31/01/2022). The year 1969 would be a good starting point not only for digital sound recording on physical media - first for LP, then CD, DVD, SACD and BD - but also for audio files.

What connects both these media - the carrier and the Internet - and what is necessary for having sound coming from the speakers or headphones is a digital-to-analog converter, also known as a DAC, or simply - a D/A converter. Such as the DAC-01S from the Polish company MuzgAUDIO, tested by us this time. Its founder and designer is Mr. KONRAD SIEMIENTKOWSKI.

| A few simple words…

KONRAD SIEMIENTKOWSKI
Owner, designer

⸜ KONRAD SIEMIENTKOWSKI, head of the MuzgAUDIO

I HAVE BEEN BUILDING AUDIO DEVICES ever since I was a kid (all emphasis - ed.). At first, they were very primitive constructions built from whatever was at hand, but with time the designs evolved into more and more sophisticated, until I finally developed the most advanced ones. It coincided with my electronic education. After obtaining the title of electronics engineer, I quickly started working in the automotive industry, where I was involved in designing of infotainment systems, in particular USB devices, and later wireless (inductive) charging. After six years, I became a senior development engineer.

All this time, after hours, I worked on my audio projects that were well received by people and quite popular. Wanting to spend more time on my own projects, I quit my job in automotive and founded the MuzgAUDIO company.

I have been fascinated by the subject of digital-to-analog converters for about 15 years. During this time, I have built and tested many solutions. Subsequent solutions were more and more thoughtful and extensive, which had a positive effect on the sound. About 10 years ago, a certain person interested me in the top Sabre chip - the ES9018S. Initially, I was concerned about its complexity, but the first device featuring this chip was ready sometime in 2012.

Unfortunately, despite the relatively large financial investment, the sound was only of average quality. It bothered me and, using the experience gained earlier, I started to modify the power supply. And - eureka! New discrete controls designed by me changed the sound of the device beyond recognition. Encouraged by the positive changes, I started to design new versions of each of the modules, which I then compared with the previous ones. There were 12 types of regulators, 5 types of analog stages, 2 types of digital modules, 5 drivers, 2 USB modules.

After a few years, when the device seemed ready, ESS released a new, clearly superior chip - ES9038PRO. I quickly accepted the challenge, but just as quickly found out that I had to rebuild the whole device to use the new chip. It was quite a challenge, but I already had a lot of practical experience gained when developing the previous device. Initially, designing an analog stage seemed almost impossible, and later I built as many as four of them plus one based on tubes. The fun started anew, but the results exceeded my expectations.

⸜ MuzgAUDIO’s workshop

What distinguishes all my products, including the DAC-01S and DAC-01T, is the fact that the solutions used in them are entirely proprietary. The entire power supply section is built on the basis of discreet solutions I developed, selected for a specific application. The power supply is fully linear and features several sections. Even the display backlight is analog. There are as many as 7 transformers with a total power of approx. 100 VA, 22 voltage regulators, including 20 discrete ones.

The power supply is divided into domains: digital, analog right channel, analog left channel, USB section and clock generators. The latter also deserve attention as they are proprietary, 4th generation analog generators developed at MuzgAUDIO and improved over the years. They are characterized by an extremely low phase noise in a wide range and a tolerance of 1 ppm.

As the device was designed to directly drive power amplifiers, in addition to the high output signal, I put a lot of emphasis on clear and intuitive user interface. Thanks to the 4.3" IPS color display, a convenient to use remote control, the DAC, despite its advanced functions, is simple and intuitive to use.

The output stage is based on two very fast, low-noise operational amplifiers per channel. The output opamp offers a very high current efficiency, which allows it to easily deal even with higher loads. These factors allow the DAC-01S to easily drive power amplifiers from small tube ones to powerful solid-state ones. KS

▌ DAC-01S

CURRENTLY, THE MuzgAUDIO LINEUP includes only one D/A converter. The manufacturer offers many ready-made modules, including power supplies and amplifiers, and the DAC-01S is largely based on them. There in only one model, but available in two versions - a semiconductor and tube ones (respectively: 'S' or 'T' included in the name); it is about the method of amplifying the signal in the output circuit. We are testing the semiconductor version costing PLN 25,000 - for the DAC-01T version you have to pay PLN 10,000 more.

The device is quite large, it is heavy and looks very solid. Its appearance resembles measuring devices from the 1970s and 1980s and is absolutely utilitarian. It features an aluminum front, available in two colors, and a beautiful knurled knob on the side. The center is occupied by a large, color IPS display. The entire chassis is made of aluminum and inside it has been damped with bituminous mats, which makes it deaf when tapping it. This means it will not vibrate once in operation.

The DAC offers four digital inputs - 2 x RCA, optical Toslink, USB - and it is a balanced design. S/PDIF inputs accept PCM signal with sampling frequency of 32-192 kHz and DSD64 DoP, USB input accept PCM signal 32-384 kHz and DSD to DSD512 (natively). There are two analog outputs, balanced XLR and unbalanced RCA. They are rated, which is quite a rare case, according to the Compact Disc standard, i.e. @ 2 V rms for RCA and 4 V rms for XLR.

The output voltage can be changed and it is one of the many, many possibilities of signal correction offered by the tested D/A converter. The DAC-01S is the first device I know, based on the ESS Sabre ES9038PRO DAC chip, which gives the user access to ALL its options. Manufacturers usually choose them for us, which has its advantages, which, however, "sets" the sound of a given product for good. After a few hours of experiments, it turned out that I prefer one specific set of setting, but yours may be different.

One can adjust volume - it operates in digital domain with 64-bits precision - choose one of the seven digital FIR filters, turn off oversampling, select the frequency of the IIR filter, activate permanently or automatically de-emphasis, turn on the dithering system, etc. Information is displayed on the aforementioned IPS display. Changes are easy as we can make them with the big knob that also doubles as a button, or with the remote control.

What seems more important to me, however, is the fact that almost all the circuits inside were designed by Mr. Siemientkowski. From power supply, display circuit and clocks for the USB input, to the output stage. A peek inside and we know that the designer is an organized, even pedantic man. The is a modular device with each module neatly connected to the rest. I asked the head of MuzgAUDIO why he wrapped all the power cables with a heat insulating tube, to which he answered:

Above all, I care about safety of users and try to use even triple insulation on power cables. Sometimes I also use it to keep the order inside chassis. I like full feng shui. :) Where there is order and harmony, distortions have a harder time to do any harm.

The ES9038PRO chip he uses is the top design of the ESS Technology. The eight-channel DAC can be switched to stereo and even monaural mode; in the DAC-01S we deal with the former choice. In such a system, the converter benefits from much lower distortions and noise levels. It accepts PCM signal up to 768 kHz and DSD signal up to DSD1024, but the USB receiver circuit slightly limits these parameters to 384 kHz and DSD512. In practice, it doesn't matter, I don't know any files with a higher sampling rate than those.

In the USB input section we will see two solid looking clock - these were designed by the head of the company. The DAC chip also uses a nice clock, but from the Crystek company. There are integrated circuits in the output. The designer says that the I/V section is built on the basis of very fast, efficient operational amplifiers, as the manufacturer says: "quite unique on the audio market".

It is an impressive design.

▌ SOUND

⸤ HOW WE LISTENED The MuzgAUDIO DAC-01S digital-to-analog converter was tested in the HIGH FIDELITY reference system and compared to the D/A section of the Ayon Audio CD-35 HF Edition SACD player, which also worked as a transport, and also to the Mytek Brooklyn Bridge file player. As usual, I was most interested in how the Polish DAC handles CDs, and to verify my observations I used files played from the NAS using my laptop.

The DAC-01S offers a multitude of settings. The manufacturer says that its output has low impedance and high current, so it can drive the power amplifiers directly. This is one of the possible options. In my experience, however, we will achieve much better results with a high-class active preamplifier. So the DAC had output level control disabled. Of the filters, I liked the apodization filter the most, I also turned on dithering. I got a very interesting sound by occasionally turning on the de-emphasis circuit - some albums, previously a bit bright, sounded great!

The Ayon digital output was connected with the DAC’s input using the RCA → RCA Acrolink Mexcel 7N-DA6100 II cable, and the DAC was powered with the Harmonix X-DC350M2R Improved-Version power cable. The DAC was placed on the top shelf of the Finite Elemente Master Reference Pagode Edition Mk II rack on its own feet. In my system I use RCA cables and this is how the converter was tested. It was connected with the Ayon Audio Spheris III preamplifier using the Crystal Cable Absolute Dream cables.

Recordings used in the test | a selection

⸜ ART PEPPER, Art Pepper Meets the Rhythm Section, Contemporary Records/JVC VICJ-42524, K2 CD (1957/2006)
⸜ FRANK SINATRA, Come swing with me!, Capitol Records CDP 7 94520 2, CD (1961/1991).
⸜ PAT METHENY, What’s It All About, Nonesuch Records/Warner Music Japan WPCR-14176, CD (2011).
⸜ WARREN BERNHARDT TRIO, Warren Bernhardt Trio '83, dmp CD-414, CD (1983).
⸜ KING CRIMSON, In The Court of the King Crimson (An Observation by King Crimson). 50th Anniversary Box Set, Atlantic/WOWOW Entertainment [Japan] IEZP-128, „2019 Remix by Steven Wilson”, 3 x HQCD + BD Audio (1969/2019).
⸜ DEPECHE MODE ‎A Broken Frame, Mute/Warner-Pioneer Corporation 18P2-2676, CD (1982/1989).
⸜ TSUYOSHI YAMAMOTO TRIO, Midnight Sugar, Three Blind Mice/Impex Records IMP8308, Gold HDCD (1974/2004).
⸜ ENYA, 6 Tracks, WEA Records/Warner-Pioneer Corporation 20P2-2725, CD (1989).
⸜ PET SHOP BOYS, Elysium, Parlophone P915 9772 | 5099991597724, Limited Edition, 2 x CD (2012).

The MuzgAUDIO CONVERTER STAYED ON the Finite Elemente rack for quite a long time, which does not happen often. It is so because I do not have an infinite amount of time for the reviewed products. On the contrary, in the course of my work I had to learn how to assess them quickly and in a way offering proper results. Otherwise, I wouldn't be able to test as many products as I would like. So the thing is that if I don't like something during the first listening session, if no remedial measures such as changing the cables, settings, power supply etc. help me, I come to a conclusion, that it is not a product for me.

On the other hand, if something sounds in an interesting way right away, I am sure that it will do as good a job also for you, if you decide to give it a chance and listen to it in your system. Some of these products turn out to be so good that I spend more time with them, just for the fun of it. This was the case with the tested DAC-01S converter. Before I started the actual listening session, I had already spent a dozen or so hours with headphones on, with music decoded by the Polish device from CDs via the transport section of the Ayon Audio CD-35 HF Edition player.

The DAC-01S captivated me with its incredible natural sound. Compared to the D/A section in the Ayon player, it sounded more direct. The reference player presents the sound a bit further away, with more vividness, its presentation is also more velvety - I say this for lack of a better term. Interestingly, the Polish DAC sounded a bit "lower" than the Austrian player, i.e. it emphasized the lower midrange more. And the CD-35 HF is, after all, a device that sounds in a very "dark" way, at least if we compare it with most other digital sources.

It turned out very well on the ART PEPPER’s album entitled Art Pepper Meets the Rhythm Section, in the version released by JVC in 2006, and prepared with the use of the 20-bit K2 converter. The material, masterfully recorded by Roy DuNann, has a panorama typical of those times, with instruments spread over the channels. But that's why they have to be reproduced in the best possible way, there is no escaping the blurring of elements in the stereo panorama. The Polish DAC did it perfectly, with high dynamics and great timbre presentation.

I felt the same when listening to FRANK SINATRA's Come swing with me! album. This is a regular release of Capitol Records in an analog remix (from three-track tapes, the album is marked AAD) prepared by Larry Walsh, but the release is sonically excellent. I heard both the low sound of the trombones, usually muted by the devices, but also excellent cymbals, with incredibly well grasped ending elements of the American Beauty Rose.

And the voice - Sinatra played by the Polish DAC was clear, but not exaggerated. It was placed very well in space, i.e. it was shown in front of the orchestra, and the latter one was presented spaced in a semicircle. It also had a good acoustic "connection" with it - please listen to That Old Black Magic and you will know what I'm talking about.

The DAC-01S is a very neutral DAC. It really does not add much from himself and it is difficult to pinpoint a range that would be favored by it. It seems to have an open sound, but it is not bright. Neither the cymbals on the percussion, that, at times, have a high energy on Pepper's disc, nor the strong brass section on Sinatra's disc, nor even the sound of the guitar solo from PAT METHENY's CD, released by Nonesuch Records, entitled What’s It All About were bright or exaggerated. The whole was dense and saturated.

I said earlier that the Polish DAC sounds lower than the Ayon, but I have to expand it. With solo guitars - the album opens with a piece played on a 42-string instrument, and the basic version ends with a classical guitar with nylon strings - Mr. Konrad's DAC showed excellent differentiation, which made the character of the instruments really clear. Not only that, it was clear, but it had a musical sense. The DAC does not differentiate for the sake of differentiating - the sound is with it a part of the artistic creation, and it allowed it to develop and resonate. I am talking about the fact that the treble is strong and clear, but the upper midrange is stronger and it sets the tone for the whole.

Usually, when we talk about a "strong upper midrange", we talk about brightening of the sound. This is because a large part of digital devices could not cope with the issue for many years - the designers wanted to provide the most detailed sound possible and, not knowing how to do it, they let it be based on a bright treble and upper midrange. Today, when digital devices can offer an excellent resolution, as exemplified by the DAC under review, there is no question of brightness of the sound. And yet the presentation is open and resonant with it.

| Our albums

⸜ WARREN BERNHARDT TRIO
Warren Bernhardt Trio '83

dmp CD-414, COMPACT DISC (1983)

TO SEE HOW THE POLISH DAC CAN HANDLE strong, uncompressed cymbals, I reached for one of the early dmp albums. Digital Music Products was one of the first labels to specialize in recording and publishing music on digital media - Compact Discs and DAT tapes - mainly jazz. It was founded in 1983 in Minneapolis, Minnesota, by TOM JUNG, right after he left the Sound 80 recording studio.

The Warren Bernhardt Trio '83, the album by the pianist WARREN BERNHARDT, recorded with Eddie Gomez and Peter Erskin, was one of the first, if not the first, albums released by this label. The material was recorded directly on a stereo tape recorder, by the entire trio, without overdubbing other tracks. And the tape recorder was special - the digital reel-to-reel tape recorder with a fixed head, the MITSUBISHI X-80. Recordings took place over three days, January 17, 18 and 19th 1983, and were made at The Barn, a studio located in New York.


The X-80 was an unusual tape recorder that digitally recorded material on an audio tape. The recording was done with a depth of 16 bits and an unusual 50.4kHz sampling rate, which had to be converted to 44.1kHz - which was quite a challenge at the time. The advantage of the tape recorder was that it was possible to mount tapes on it and edit them, just like on an analog tape recorder, with a razor blade - and so was the disc in question prepared. More about this technique HERE and HERE.

The effect of these treatments, however, is dazzling - high dynamics, beautiful, sonorous high tones and precise bass. ♦

LET'S GET BACK TO THE TESTED DAC. All three top SACD players that I have dealt with recently, and these were - next to my Ayon - ESOTERIC K-01XD and ACCUPHASE DC-1000/DP- 1000, sounded more creamy. Creamy, that is, darker and denser. The difference in color rendering, I have to say this, was not big. Given the price spread, significantly smaller than the price difference.

Because to the great dynamics of the Polish device, its excellent resolution and open sound, one can add also a well-controlled bass and a natural midrange. I listened to a few DMP records from the early 1980s with material recorded "live", albeit in a studio, on a Mistubishi X-80 digital tape recorder. Let me repeat that this device worked with a resolution of 16 bits and an unusual sampling frequency of 50.4 kHz. Transferring it to CD format, or an asynchronous conversion to 44.1kHz, meant the loss of some information. Nevertheless, the sound of these recordings is outstanding (see above for what I wrote regarding the Warren Bernhardt Trio '83).

The Polish converter did an excellent job, because it did not harden the attack, as it often happens with many modern DACs, nor brighten the treble. The treble was slightly "grainy", but this is an inherent part of the Mitsubishi cassette deck sound. Nevertheless, the presentation was exceptionally pleasant and perfectly musical. And the dynamics was impressive again ...

With recordings with a highly compressed signal, such as PET SHOP BOYS’ from the Elysium album, the sound will not be dynamic, that's clear. Fortunately, despite the compression, the DAC did not harden their sound. It was nice, rocking, even slightly soft sound with a nice timbre. The dynamics suffered the most, of course, because the whole thing "crashed" energetically and was clearly calmed down. It was, however, and probably that’s what is most important (from my point of view), musically interesting.

▌ SUMMARY

CERTAIN THINGS CANNOT BE AVOIDED and it is no coincidence that good audio devices are expensive, and the best ones are very expensive. The Polish DAC is, for a completely unknown company, an extremely expensive element of the system. And yet, thanks to its advantages, it can be the cheapest element in it, even twice as cheap as an amplifier, loudspeakers, etc., and one will still look for sound improvements elsewhere in the system.

It offers excellent dynamics and resolution, and it also sounds in a very open way. It delivers a very nice tonal balance. More expensive devices from the world's leading brands are more vivid and differentiate the sound better within the bodies of the instruments. However, for this improvement you will have to pay twice as much for it to even make sense. Here and now, DAC-01S from MuzgAUDIO is a product with exceptional sonic qualities. Its sound can be still tuned by choosing various types of digital filters. So we award him the ˻ RED FINGERPRINT ˺ award.

▌ DESIGN

THE APPEARANCE AND DESIGN OF THE DAC BY MuzgAUDIO are absolutely utilitarian, i.e. they are subordinated to the function they perform. In the visual design, you can see elements that are supposed to make it look more attractive, but it does not change the first impression. It tells us that we are dealing with a "tool".

⸤ FRONT AND REAR Its chassis is bolted together of aluminum plates and stands on four solid feet. The lower plate has been additionally reinforced with a galvanized sheet, which shields the circuits inside and stiffens the whole structure. To control vibrations, all walls were covered with CTK bitumen mats from the Premium series. These mats are used in the automotive industry to soundproof the interior of the car - as you can see, the experience gained previously by the designer came handy.

Company materials read:

Top-class, self-adhesive anti-vibration mat for the most effective damping of vibrations, noise and acoustic resonances of car body elements and upholstery, yachts, machines, industrial devices, housings of computer equipment, electronics and household appliances. Very low weight, high efficiency, high flexibility and adhesion to the substrate. Price per package: 15 sheets, dimensions 370x500 mm (2.78 m2), mat thickness 2.2 mm, aluminum foil thickness 0.1 mm (100 micrometers). One of the lightest of its kind anti-vibration material based on butyl produced in Europe!

⸜ source: CARAUDIOSKLEPY.pl; accessed: 31.01.2022.

The front panel of the DAC is a thick aluminum plate and is available in natural aluminum or black anodized versions. On the right side there is a large, comfortable to use knob/button with knurling, used to navigate through the menu and change the volume. In the center there is a large, color display, on which we can read the details from the menu, and after exiting it, the selected input and digital signal parameters; in addition to the name of the input, there is also its symbol. The menu is in Polish, which means that it was programmed independently. And on the left there is a rugged, industrial piezoelectric power switch with a white, illuminated frame.

On the back there are solid Neutrik sockets. On the left (looking from the rear) there are pairs of balanced XLR and unbalanced RCA sockets - these are the analog OUTPUTS. The next group are digital INPUTS: USB, Toslink and two RCAs. And on the left there is an IEC power socket and a mechanical switch that completely cuts off the power from the device. The IEC socket with gold-plated contacts and an integrated fuse (IC-03) are products of the Furutech, model IC-03 (G).

⸤ INSIDE On the inside, the Polish DAC, on the one hand, resembles the products of other good companies, and on the other, it differs significantly from them. Let's start with the similarities. DAC-01S is built from modules. The manufacturer can use them in various products, in various configurations, which greatly facilitates the designing process. On the other hand, if a given module is improved, I see no reason why the company should not offer an upgrade program.

As in the case of the best devices, most of the tested DAC chassis space is occupied by the power supply section; I counted seven power supplies. Each module is powered separately: the board with inputs, boards with clocks for the USB input, converter, display, as well as the analog output circuit - here, each channel also has its own power supply. The latter are the greatest of all. Importantly, the power supplies are discrete, they do not use integrated stabilization circuits, but designed in-house circuits featuring bipolar transistors. There are small SMD boards with such filters and voltage regulators next to individual circuits.

The input circuit uses its own PCB labeled "Saber Simple Input Board". A smaller Atmel board with a ready-made receiver circuit that converts the USB signal to IIS is connected to it. Above it there are two wonderful boards with precise also proprietary clocks - the sticker says that they operate with a precision of 1 ppm.

On the side there is the actual DAC. It was also divided into two parts: the board with the ESS Sabre ES9038PRO DAC chip with the Crystek clock and voltage regulators. Below, you can see a larger PCB with the output circuits. Since we are testing the semiconductor version ('S' in the DAC-01S designation) these are semiconductor circuits, fast integrated circuits. Outputs are mutated using Siemens relays. Let us add that the board with the TFT display and the driver for it was also designed and programmed by Mr. Siemientkowski.

⸤ OPERATION The DAC offers a lot of settings, one can also activate the volume control. Thanks to the large display, all the operation is extremely simple, although the signs on it could be larger. Also, the blue color of the signs is not legible enough. However, these are minor details.

You can navigate through the menu using either the knob/button or the remote control. This is a plastic, universal and quite ergonomic remote.

The DAC-01S is one of the most technically interesting D/A converters I have seen recently. And in addition, it is based largely on the proprietary MuzgAUDIO solutions. Respect. ■

▌ Technical specifications (according to the manufacturer)

Supported sampling frequencies:
– S/PDIF input – 32 -192 kHz and DoP64
– USB input – 32 - 384 kHz and DSD64 - DSD512 (native)
Output signal: RCA – 2 V rms ׀ XLR – 4 V rms
Output impedance: 100 Ω
DAC: ESS ES9038Pro
THD: <0.001%
S/N: >122 dB
Dynamic range: >132 dB
Frequency range: 0 - 20 kHz +/-0.1 dB
7 digital filters FIR and Non-Oversampling mode
Volume control: -128 dB to 0 dB, in 1 dB cs
Dimensions: 460 x 360 x 150 mm (W x H x D)
Weight: 12 kg
Power consumption:
Standby: 2 W
Operation: around 40 W