⌈ 432 EVO is a brand owned by the Klinkt Beter company, founded in 2013 by FREDERIC VANDEN POEL. It specializes in the production of audio files transports (music servers). Its lineup currently includes four models: Standard, High-end, Aeon and the top Master; we are testing the latter.⌋

VO 432 MASTER IS A TRANSPORT OF AUDIO FILES. It decodes audio files stored on internal or NAS disks, in formats such as WAV, FLAC (PCM) and dsf and dff (DSD), in any resolution and converts them into digital signal - PCM or DSD. It can also serve as a server because of an SSD installed inside. In the tested unit it had a capacity of 2 TB and came from Samsung brand. For an additional 550 EUE 8 TB disc can be installed instead.

The device is available in four different versions, differing in the degree of advancement of the power supply, but not only that. The Standard version does not feature a dedicated USB card and has one power supply. The High-end version already features a dedicated USB Audio card from SOtM and an additional power supply for that card, and Aeon also has a Superclock clock card.

The tested version, "Master", benefits from the most advanced, three-part power supply circuit. Therefore, the 432 Evo Master set consists of two devices - a transport and power supply, placed in very similar aluminum housings. The chassis are extremely utilitarian and you can see that the man behind the company comes from a world where such devices are mounted in racks, so they do not have to be eye-catching. In other words: they don't have to attract the eye. And they do not.

The designer of the tested transport is Frederic Vanden Poel, as we read in the company materials, one of the more experienced software engineers, who has been working in the IT industry for over twenty years, specializing in Linux-based systems. Dissatisfied with the software used to play music, as well as with the devices that used this software, he designed such a device in his own way, using computer modules and writing his own playback program.

In addition to various types of digital filters that correct the sound - we have as many as ten at our disposal! - he also offered something absolutely unique, namely the ability to "tune" the music switching from 440Hz tuning to 432Hz one. This conversion is performed digitally by changing the sampling frequency. It used to be associated with a change in the tempo of a track, but since efficient DSP circuits are available, it is corrected constantly and only the pitch of the sound changes (here by 8 Hz), and the tempo remains unchanged. The manufacturer ensures that this is done without losing any resolution.

This solution seems to be crucial for Frederic Vanden Poel, therefore the transport is sold under the 432 Evo brand.

| The issue of tuning

⸜ The Dudkiewicz / Niedziela / Orzechowski / Stankiewicz / Tokaj / Wyleżoł Piano Sketches played using 432 Hz tuning

IT IS RARE that an AUDIO COMPANY would have such a clear modus operandi, included in its name: 432. This '432' refers to a frequency of 432 Hz which is sometimes used as apposed to the 440 Hz. What is all about? It's about the tuning of the instruments. The classic one, described in the International Organization for Standardization, bears the ISO 16 symbol and says that the A1 note, lying above the middle C, has a frequency of 440 Hz; it is known as the "Stuttgart Pitch".

But it wasn't always like that. Historically, a tuning could range from A-415 in Baroque music to A-465 in 17th-century Venice. The manufacturer cites other examples, such as the very low tuning of the A-392 in 18th-century France, which over the centuries was normalized to 430 or 435 Hz. In discussions about the best tuning, however, the name of Giuseppe Verdi is the most frequent one who, disgusted with the constant changes, proposed A5 = 864 Hz (ie A4 = 432 Hz), a concert tuning, later called the "Verdi Pitch". His most famous work - Requiem from 1874 - was written in the "Diapason Normal" tuning, or A = 435 Hz, but later the composer suggested that 432 Hz seemed to be the better choice.

And one could stop there, after all, it is "only" a slight lowering (only by 8 Hz!) of the sound, right? One could, had it not been for the fact that it gives different sonic effects, and because this issue has been „polluted” with a huge amount of nonsense and myths. The followers of the 432 Hz refer to either the "sacred geometry" of Pythagoras, or to the Schumann resonance frequency, or to - the aforementioned - Verdi.

The truth is, that indeed A=432 sounds a bit different from A=440, but it is difficult to pinpoint a clear "winner". The manufacturer cites research carried out by Maria Renold, which showed that 90% of listeners prefer the 432 Hz tuning (Of intervals, scales, tones and the concert pitch C = 128 Hz). However, these are not conclusive data. So, in my opinion, it is up to the musician and the audience to decide which one is better for him. For example, Adam Czerwiński prefers '432' and that's how he recorded the Dudkiewicz / Niedziela / Orzechowski / Stankiewicz / Tokaj / Wyleżoł Piano Sketches (AC Records ACR 013, 180 g LP, 2019; review HERE).

Alexander J. Ellis, who researched this phenomenon, in the article On the Musical Scales of Various Nations, points out that the 432 Hz tuning appears quite often in the history of music, but it is not the most common choice at all (more HERE; accessed on March 9, 2022). However, it IS a choice, and therefore the 432 Evo's proposal, when we reject all myths, is really interesting. What's more, the manufacturer offers several other frequencies, so we can conduct our own experiments.

For more information, see Debunking 432 Hz: Is there a superior tuning standard? ♦

▌ Technology

432 EVO MASTER IS FEATURES two modules - the proper transport and linear power supply. Both utilize similar, simple housings, the only thing that can be said about them is that they are solid. They are connected by three cables with active Sbooster filters. The 432 Evo Master is in fact a specialized microcomputer - on its back panel you will find all the sockets that can be found in a classic computer.

A brief digression. Two very different groups have emerged among the manufacturers of transports and audio files players. The first of them comes from "computer guys" who started their adventure by copying mp3 files and modifying their "PCs" and "macs" - and their software - in order to "get" as much music out of these machines as possible. If they later founded an audio company, their products are a simple translation of this experience. The second group also features computer engineers, but those who decided early on to follow the path of programmed DSPs and other circuits, departing from the classic computer.

The products of these groups differ fundamentally. The former focus on the greatest possible number of settings, and modifications offered for the user’s disposal. They ultimately come from the DIY industry in which people like them "operate". Others focus on the "completeness" of solutions and their "user-friendliness". Their devices are simple to use and look like any other audio product, such as a digital-to-analog converter. Vanden Poel is a "computer scientist," so it should come as no surprise that his devices are simply specialized computers.

They are based on a minicomputer motherboard with a quad-core Pentium processor. The designer has written his own BIOS for it, which turns off almost all its functionalities, and the processor works only with the proprietary software. Separate cores support the player, filters and controls. For transport, we only use a LAN cable connecting the device to the home network and the Internet. In turn, we use a USB signal from a separate sound card, via the USB 3.0 port. This card is clocked with an advanced clock with separate power supply.

The device is equipped with a CD-ROM drive, with can be used to rip CDs to the internal memory. The latter is based on SSDs with a capacity of 2, 4 or 8 TB (to choose from), mounted in a nice way, so that they vibrate as little as possible. The SATA links, that is, from the CD transport and from the SSD drive, use special noise-reducing filters in the path.

⸜ CONTROL Controlling the device is divided into two parts - one part is performed with the use of a computer, and the other through a control application (it is also an indication of what type of designer we are dealing with). We set the parameters of the available filters from the VortexBox website, i.e. via the computer and also via the computer we can copy files to the SSD drive in the transport. In turn, playing music was entrusted to applications working with Linux. I used Roon during the test.

The transport plays files stored on an SSD drive, and can also connect to a NAS drive. If our app allows it, we can also play files from streaming services such as Tidal and Qubuz. We can use it to play any files, regardless of the sampling frequency and resolution - the limit is only what the digital-to-analog converter can do.

NOTE - the 432 Evo Master does not fully decode MQA files! Vanden Poel dislikes this solution very much. The first „unfolding” is performed in the Roon-controlled device, but the second stage is not performed at all. It can be done in an external DAC, but only if we set the server to "bit-perfect" mode, ie turn off upsampling and 440 Hz → 432 Hz conversion. The Mytek Brooklyn Bridge player showed that the 432 EVO Master sent MQA files to it, but did not turn on any of the LEDs, indicating that the files had been changed on the way.

▌ SOUND

⸤ HOW WE LISTENED The 432 Evo Master audio files transport was placed on the top shelf of the Finite Elemente Master Reference Pagode Edition Mk II rack. Since the length of the power cords did not allow me to place the power supply on the bottom shelf of the rack, and that’s where I had some room for it, I had to put them on top of each other - the power supply on top and the transport underneath it. I put Acoustic Revive CP-4 and RPI-5005 washers under the feet.

The transport was connected to the Internet network via my system consisting of a double LAN SILENT ANGEL N16 LPS switch, with its two modules in series, powered by a TIGLON TPL-2000A cable and a TIGLON TPL-2000L LAN cable; more about it HERE |PL|. The signal was decoded in the D/A converter sections of the SACD AYON AUDIO CD-35 HF EDITION player and the MYTEK BROOKLYN BRIDGE file player; I also used the MYTEK LIBERTY DAC II D/A converter.

The transport was powered using the HARMONIX X-DC350M2R IMPROVED-VERSION.

⸤ Recordings used for the test | a selection

→ PLIKI
⸜ DIDO, Still on My Mind, BMG/Tidal Master, FLAC MQA Studio 24/44,1 (2019).
⸜ FINNEAS O’CONNELL, Optymist, Interscope Records/Tidal Master, FLAC MQA 24/88,2 (2021).
⸜ ART BLAKEY, Moanin’, Blue Note/Tidal Master, FLAC MQA Studio 24/192 (1958/2014).
⸜ CANNONBALL ADDERLEY, Somethin’ Else, Blue Note/Tidal Master, FLAC MQA Studio 24/192 (1958/2014).
⸜ NAKANO MAYO PIANO TRIO, Sentimental Reasons, Briphonic, Direct Master Files WAV 24/192 + DSD64 (2017).
⸜ ALEXIS COLE, A Kiss in The Dark, Chesky Records, Master Files WAV 24/192 (2014).
⸜ JOHN COLTRANE, Blue Train, Blue Note/Classic Records HDAD 2010, rip z DVD-A 24/192 (1957/2000).
⸜ CHARLIE HADEN & CHRIS ANDERSON, None But The Lonely Heart, Naim label, WAV 24/96 (1997).
⸜ YES, Close to the Edge, Atlantic Records/HD Tracks, FLAC 24/192 (1972/2014).
⸜ MIKE OLDFIELD, Crises, Mercury/HD Tracks, FLAC 24/96 (1978/2013).

→ SACD/COMPACT DISC
⸜ NAKANO MAYO PIANO TRIO, Sentimental Reasons, Briphonic BRPN-7006, Direct Gold CD-R (2017).
⸜ ALEXIS COLE, A Kiss in The Dark, Chesky Records JD366, CD (2014).
⸜ DIANA KRALL, This Dream Of You, Verve Records UCCV-1181, SHM-CD (2020).
⸜ CHARLIE HADEN & CHRIS ANDERSON, None But The Lonely Heart, Naim naimcd022, CD (1997).
⸜ YES, Close to the Edge, Atlantic Records/Warner Music Japan WPCR-15905, 7” Cartboard Sleeve, SACD/CD (1972/2014).
⸜ MIKE OLDFIELD, Crises, Mercury/Universal Music Japan UICY-75880/1, 2 x SHM-CD (1978/2013).

IN A SHORT TIME I HAD THE POSSIBILITY to listen to two high-class, but completely different conceptually and sonically, file transports: AURENDER N20 |PL| and the 432 EVO MASTER, which was the subject of this test. In both cases, special attention was paid to reducing jitter, by means of sophisticated power supply sections and complex clock systems, as well as reducing vibrations, which also affect time distortions. Their USB outputs have been specially treated and protected against RF noise. Both devices also had built-in SSDs, so they were identical products from the utility point of view.

As I’ve said, they offered completely different performance. Although from the point of view of a classic IT engineer, file transport - with basic precautions - should not have ANY effect on the sound, the example of these two devices shows that it does have a basic, shaping effect. I have been writing about it for years, but only recently this knowledge, because it is simply a practiced knowledge, is beginning to break through to the wider public. Fortunately, engineers who understand the importance of the experimentation and are not afraid to apply their conclusions from those can offer us something much better than a "computer".

I listened to the 432 Evo Master transport for a long time without comparing it with the Ayon Audio SACD player and without relating its sound to the transport section of the Mytek Brooklyn Bridge file player.

This sound fascinated me. It was completely different than from my Ayon, but it also sounded in a different way than the already mentioned Aurender. I sat there listening and thinking that this type of a "tool" should be used in the best recording studios, where it would work as a "player" of DAW files - Digital Audio Workstation, i.e. as a digital player of recorded files . The musical world would be better then.

The thing is that the tested transport is an extremely resolving device. It is rare in file players, and in studios the fact that the files have separate tracks (files for the left and right channels, which makes a difference!) and that it is made up for it with selectivity and opening up the treble. On the one hand the selectivity has its own „golden mean”, there cannot be too much of it, nor too little, as there can never be too much resolution. It allows, as in this case, for excellent tonal differentiation and above-average scaling of dynamics.

Let's start with tonality, that is timbre. The '432' is able to show even small changes in its intensity and pitch, even if the instruments are close to each other on the scale. This means that it perfectly differentiates harmonics. Thanks to this, the presentation is extremely rich internally, and therefore it is interesting. This is why, I am sure, the tested device is so impressive.

It didn't matter whether I was listening to new releases digitally recorded in the Pro Tools system, like the Hurricane from the DIDO album entitled Still on My Mind, or to the excellent FINNEAS O'CONNELL from < i>Optimist, or jazz classics: ART BLAKEY from Moanin' and CANNONBALL ADDERLEY from Somethin' Else from digital copies of hi-res tapes analog. The sound was of the same class.

The transport showed remarkable sound stability, showing the same advantages with every musical material I played. It also had full tonal control. Not only did it show its character, depending on who played a given instrument, who recorded the instrument, and - finally - how the file was encoded, but also showed the instruments in a compact, well-defined way, which made them different in that, i.e. character, not just timbre.

The second thing that makes this device very impressive is the dynamic scale it presents - it is huge. It is the "soft underbelly" of audio files based systems. I have been observing the changes that have been taking place in this respect for over a dozen years. For a long time the prognosis was rather bad as the file players were anemic and "blurred" the sound. It’s been changing constantly, but recently, in the last two or three years, the improvement in this respect has been clearly noticeable.

In my opinion it is still not a quality comparable to a good CD and SACD player, not to mention the master tape. Now, however, with the best devices, such as the tested 432 Evo Master, the dynamic range is so large, the sound is so good that without direct comparison we will not be able to tell the difference. And certainly not with the transport we are talking about, which is above average in this respect.

When we listen to recordings from the "golden age" of jazz, that is, from the 1950s, for example from Somethin’ Else, the device surprises with full bodies of instruments. In addition, bodies are very well defined. On the other hand, the voices of Dido and Finneas, mentioned above, were big and really strong, but less differentiated within them. It is not the fault of the transport, it only showed the change that has occurred. The result is not only a change in technique, but also in sound: from simple, based on minimal post-production analog recordings to very highly "produced" digital recordings, it is possible to trace a slow degradation of resolution and differentiation in the name of the "wow!" effect.

The sound of the 432 Evo Master, however, is not the same as the sound of the SACD player it was compared to, or even the sound of the Aurender N20 file transport. In fact, it differs so much from both that you can even talk about different sonic aesthetics. And that's good news. The choice, its possibility, is what is extremely valuable in audio and worth protecting. When everything sounds the same, it means that we no longer live (heaven, nirvana, etc.), or that we are alive, but in a totalitarian state. There is no such thing as "absolute sound", there are only attempts to reach it.

Anyway, the tested transport showed a strong, precise foreground. It was not hardened, because even when at some point in the songs of Dido and Finneas a strong fragment entered, the sound remained natural, it was not unpleasant. And it is about a highly compressed signal (it is about a compressor, i.e. compression of the audio signal, not file compression), and therefore difficult to reproduce properly.

But what I am talking about, i.e. the open midrange and strong, expressive foreground, ultimately define the character of the 432 Evo Master. The transport places sound close to us, without the far reverberation that I had with the Aurender, but which I heard mainly with the Ayon Audio CD player. Interestingly, the Belgian files transport did not blend everything into a "wall of sound", because even within the strong foreground, where it is the most happening in its case, it retained excellent selectivity and separation. That's why I said it would be an ultimate tool in recording and post-production (mixing and mastering) studios.

Its sound is not as warm as the Aurender N20’s. On the other hand, the Ayon does not seem warm when playing SACDs and CDs, but it delivers a clearly lower sound. The closest to what the tested transport showed with the Ayon D/A converter was the sound of the GRYPHON ETHOS CD player, at least when it comes to the character of the sound. On the other hand, Aurender would belong to the group that would include MARK LEVINSON No. 512 and SOUL NOTE S-3 v2. The Ayon Audio CD-35 HF Edition would be somewhere in the middle.

| 440 Hz vs 432 Hz AND OTHER FEATURES

⸜ Settings used during the test

DIGITAL FILTERS, BECAUSE THAT’S WHAT WE ARE TALKING ABOUT, made available to users by the constructor of the tested transport change its sound more than replacing a power or USB cable. They largely determine how the 432 Evo Master sounds like.

Basic conversion, which brings the pitch of all recordings down to 432 Hz, is perfectly audible. Indeed, the sound seems to be a bit lower and better filled in. The presentation is bigger and more pleasant with it. The difference is not big, but so important that if we compare a few files "with" and "without" conversion, we won't go back to the '440'.

This does not mean, however, that we get it for free. Every operation on a digital signal leaves its mark on it, no matter what computer specialists think. In this case, the sound is a bit less transparent and clear. It seems as if its micro-dynamics were slightly smoothed for the sake of greater vividness and depth of the sound.

But digital filters can help. Recommended by the Polish 432 Evo distributor, Soundclub, "Archimago's imp + Evo 2" turned out to be the most interesting one. It added even more vividness to the presentation, but also deepened the sound stage, separating the instruments standing closer to us from those farther away. This is still not a lot of depth, the foreground is still the most important, but with this filter the deeper layers are richer in meaning and better differentiated. The sound is a bit less selective than without it, but it sounded more like what I know from SACDs.

And then there is an upsampler, called here "Plugin", and a filter called "Bass authority". The latter did not change the sound in any clear way, at least in my system, with the two D/A converters I used. On the other hand, the upsampler influenced the sound a lot, but for me it was a wrong way - with more saturation, but also less control. Therefore, the upsampler was turned off during the listening sessions. ♦

FINALLY I would like to share a few comments regarding DSD file playback. I compared a few discs that I have in both PCM and DSD (and also on physical discs) with curiosity and I must say that PCM files fared better. The recordings encoded in DSD had a slightly colored lower midrange and a withdrawn upper midrange, which made the 432 Evo Master not so remarkably resolving. On the other hand, PCM files, especially those with high resolution, but not only those, were perfectly balanced and sonorous.

▌ SUMMARY

SO THE 432 EVO MASTER IS a device in many ways unique. It is dynamic and resolving, but also very focused on tonal differentiation, and thus emotionally expressive. The resolution allows you to appreciate the transition from 16-bit to 24-bit files. The instruments gravitate with it towards the foreground, but they are perfectly separated, and therefore legible. The midrange is open and strong, also in its higher range. This is why readability is so good, as is selectivity.

Transport does not exaggerate in drawing contours. It is also not a "warm" sound, it's not that type. So I would treat this device as a precise tool for "extracting" information from files, and I would shape the timbre with a D/A converter and cables. At the same time, it will work better in systems where the color is on the warmer side than in expressive ones. This is an example of the fact that playing files is an art that matures with time and that allows even us mortals to get closer to the "studio".

▌ DESIGN

FILE TRANSPORT 432 EVO MASTER consists of two parts: proper electronics and power supply. Both are housed in very similar, low aluminum housings. They look like enclosures manufactured for the DIY market, which can be used by designers of amplifiers, power supplies and other devices. Their mechanical structure is similar, that is, most elements of the chassis are bolted to the rigid heat sinks. Interestingly, these heat sinks are not used, no components/elements inside were fixed to them. So they only play a decorative and mechanical role.

They differ in the front and back panels. In the transport, there is a CD-ROM drive slot in the front, an a power switch. The rear of the power supply is made of a thick sheet of aluminum with the names of the outputs engraved on it, while the one in transport is thin and only varnished. This seems to be a big oversight as it all looks like a temporary solution, which it is not.

Three power cables (12, 12 and 9 V) lead from the power supply to the transport section. They are made in such a way that from the power supply side they are terminated with solid plugs, four-pin gold-plated Neutrik plugs, and from the transport side with classic, though gold-plated, power plugs. The individual cables are color-coded so that they don't get confused. Besides, I am not the only one who thinks so. The distributor glued strips of tape to the housing, corresponding to the colors of the heat-shrinkable sleeve on the power supply connectors. In any case, it is really easy to make a mistake, so it's worth checking the manual and checking three times before making any connections. And yet it could be done differently, from the transport side, by dedicating a different plug to each power supply.

⸤ TRANSPORT Transport 432 Evo Master is built of three main modules: microcomputer, sound card and clock. Added to this is the Teac CD-SN250-000 slotted transport, with which you can rip CDs, as well as an SSD drive - here 2 TB, from Samsung. The latter is mounted on springs and pressed down with vibration-damping material, thanks to which it is not so susceptible to environmental vibrations.

The microcomputer is an ASRock J54040-ITX motherboard with a Pentium J5040 quad-core processor (up to 3.2 GHz), four SATA ports and passive cooling, designed for example for the NAS. This is where the player circuit, programmed by Klinkt Beter engineers, works, as well as all digital filters. After decoding and "unpacking" from the files, the digital audio signal is sent to the output board.

Here, a ready-made USB tX-USBexp chip from SOtM was used. SOtM is a Korean manufacturer specializing in decoding and transferring audio files. It offers both complete devices and components for "tweaking" a PC. The tX-USBexp card is equipped with a super-fast USB 3.0 output.. Its design pays attention to noise reduction, which is minimized in "specially designed filters".

A separate chip is responsible for the clocking of the card, made on a high-quality printed circuit board (of the same class as the card itself). It is a complete SOtM sCLK-10EX clock chip. It produces four different reference clocks and is equipped with noise reduction circuits.

⸤ TRANSPORT The power supply was made independently by the 432 Evo company. They are actually three separate power supplies, two for 12 and one 9 V. They supply power to the microcomputer, clock and sound card separately. They are based on very large toroidal transformers from SBOOSTER; the same company provides power cables with small boxes "Sbooster BOTW" (BOTW = Best Of Two Worlds). Active input and output buffering filters are placed in those boxes. Let me add that Sbooster is a Dutch company founded and run by Wiebren Draaijer and Karin Hoks.

The power supply circuits feature discrete rectifier bridges with super-fast diodes, as well as extensive voltage stabilizing circuits, supported by large capacitor banks. In front of each transformer there is a passive filtering system that minimizes noise introduced to the device from the AC power line. ■

▌ Technical specifications (according to the manufacturer)

Digital output: Superclock based dedicated USB 3.0 output supporting USB Audio Class 2.0 
Connectivity:
⸜ Ethernet, 1x RJ45 gigabit
⸜ 1x USB DAC output
⸜ 2x USB 3.0 – for backup or connecting additional USB DACs
⸜ 2x USB 2.0 USB for additional DACs
⸜ KVM, VGA, DVI, HDMI and keyboard service port

Supported file types: DSD, WAV, FLAC, MP3, ogg vorbis, aac, passthrough MQA
Supported signal types: PCM and DSD, any resolution and sampling frequency

Dimensions: 435 x 325 x 60 mm (W x H x D; 69 mm incl. feet)
Weight:
⸜ power supply – 8.2 kg
⸜ server – 5 kg