⌈ XACT is the latest brand from MARCIN OSTAPOWICZ and joins JPLAY and JCAT, which he runs. Formed in October 2022, it initially had only one product - the S1 file transport. Last year it was joined by USB and LAN cables and anti-vibration feet, and now we are premiere-testing the higher model of the transport, the S1 EVO. ⌋

THE DIGITAL WORLD IS GROWING at a pace that other industries can only dream of. It is trendy, and is backed by hard to imagine amounts of money. The latter are typically consumed by the military industry and by content providers on social platforms. This money is used in both good and bad ways.

The war in Ukraine shows that the future is AI-based command centers, as a senior Pentagon general recently confirmed, and in China it is being used to control and judge society straight out of Orwellian 1984 (see Geoffrey Cain, The Perfect Police State. An Expedition into China's Surveillance Dystopia). In other seemingly democratic countries, on the other hand, it serves as a tool aimed at seizing power by people who would never normally gain that power.

On the other hand, however, the data-related digital industry is helping medical diagnostics, treating people and improving their safety. And, perhaps most importantly, it allows us to listen to music in a way that not so much approaches the “analog” days but sometimes leaps over it. So “digital” is simply a tool that can be used in a variety of ways. It is thus perhaps the case that as a technology it is ethically “transparent.” When you think about it for a moment, its use in music-related fields, along with medicine, may be one of the noblest ways to utilize that big money into action.

▌ S1 EVO

TESTED IN NOVEMBER 2022, file transport S1 inaugurated Marcin Ostapowicz's third brand, XACT. Let me remind you, that the first brand was JPLAY (2011), specializing in software controlling file playback, and the next was JCAT, a “hardware” company focused on products to improve the performance of music computers (2013). XACT seems to be the point of arrival of these two, as it benefits from the developments that Marcin Ostapowicz, its chief executive and chief designer, has come up with and put into production over the years.

The XACT S1 EVO is an audio file transport and is a development of the S1, which is still a part of the lineup; two more transports are planned - in the lower and even higher price level. The manufacturer writes about the new device: “Ultimate Sound Evolution, Unmatched Analog Perfection.” As he told us at the device's launch, he had but one goal: “to make the best possible file transport.” He added that the XACT S1 is the sum of all his experiences: “You could say that the products I launched under the JCAT brand were needed so that the XACT S1 could be created.” This “research”, took more than ten years.

A file transport is a device used to convert files, either from local storage or via the Internet, into a digital signal. It receives WAV, FLAC, ALAC, AAC, mp3 (PCM) and dff and dsf (DSD) files on input and “unpacks” them delivering a digital signal in PCM or DSD format to the output, sending it out over a USB connection.

It can download files either from the network, locally from a NAS drive, or from the Internet, or from an internal SSD. Thus, it is not only a file transport, but also a server. What's more, with the change of a FLASH card, plugged into the rear panel, the device can also act as a LAN switch. The S1 EVO playbacks all popular file types, in almost any resolution - DSD natively up to DSD512 and PCM up to 768 kHz, 16-32 bits. It does not decode MQA files, leaving that to an external D/A converter. The device features no Wi-Fi connection, so you can connect it to your router only via LAN cable.

Since we've already tested the S1 model, being the first in the world to do so, we also reported on the Krakow Sonic Society meeting, where Marcin talked about the device and the files, we'll focus on what makes the two devices different (coverage from KSS → HERE ˻PL˺). First, however, the basics:

XACT S1 EVO elevates digital audio playback with its precision-engineered Master OCXO Clock, in-house developed ceramic-aluminum isolation footers and an upgraded internal music drive cable, delivering an even more refined listening experience.

⸜ S1 Evo, → XACT.audio, accessed: 24.01.2025.

“Improvement” is the key word here, because the device already in its basic form was refined. It was based on the ZENA (ZERO-Noise-Architecture) architecture developed in-house, used the best components possible for the application, as the manufacturer assured, and had a secret weapon in the form of the JPLAY control application. And this is the jewel in the crown, thanks to which the company is known, without exaggeration, all over the world.

And you don't have to look far to prove it. On the day I'm writing this, a message arrived in our mailbox from Weiss Engineering, a company whose products are found in most recording studios, and which also offers “home” products; a test of the DAC 502 Mk II → HERE. It reads:

Great news for audiophiles! We have partnered with JPLAY to offer an exclusive extended trial of their premium service. Weiss product owners can now enjoy a 60-day free trial, well beyond the standard 14-day trial period.

This special promotion is designed to give you ample time to experience the high quality sound reproduced with JPLAY and experience its full potential with compatible Weiss high-end Hi-Fi products.

It says a lot about the Polish brand.

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| A few simple words…

MARCIN OSTAPOWICZ
Owner, designer

XACT S1 AND S1 EVO ARE TWO FACES of our advanced music server. The S1 EVO version, shown for the first time at the 2024 High End show, is an improved version of the original model S1, designed for an even better sonic experience. All of the improvements mentioned below were developed entirely in-house:

˻ I ˺ MASTER OCXO Clock: The Master OCXO Clock in the XACT S1 EVO is a significant improvement in sonic capabilities over the standard, already very good oscillator we use on the XACT S1 server motherboard.

˻ II ˺ PHANTOM Music Drive Cable: using the same advanced materials and precision construction techniques as our new PHANTOM USB and LAN cables, the PHANTOM Music Drive Cable minimizes signal interference and preserves audio signal purity for files played back from the built-in SSD.

˻ III ˺ IMMOTUS Mechanical Isolation: IMMOTUS is the ceramic-aluminum isolation feet introduced in the XACT S1 EVO, the culmination of years of research and passion for improving sound quality.

˻ IV ˺ Improved software: over the past two years, XACT servers have received a series of free software upgrades that make improvements in sound quality every time.

Our JPLAY application has gained great recognition among users around the world, and its popularity is also growing in Poland, which fills me with pride. More and more Hi-Fi manufacturers are signing up for our JPLAY Certified program, which confirms the highest level of our technology. Such renowned brands as dCS, MSB and Hegel have already joined the ranks of certified manufacturers.

As part of JCAT, our hardware brand, we have introduced new versions of USB and NET cards, compatible with the Master OCXO Clock module - the same one we use in the S1 EVO. Of course, we are also preparing other innovations in the top brand XACT, which I hope you will soon read about in “High Fidelity” :) MO

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FROM THE OUTSIDE THE DEVICE LOOKS IDENTICAL to the S1. It's an attractive, curved design with an aluminum chassis and velvet front. It is no different from the previous version from the outside, not even the logo. What is new, however, are the feet. In November 2024 we tested a new product from the XACT brand, the Immotus CL and Immotus CRX anti-vibration; test → HERE. They turned out to be an extremely interesting product. The S1 Evo model features three units of the Immotus CL.

On the front panel there is only the standby button with an orange border. As we said, Martin loves simplicity and moderation, so he opted for a “black box” device, with which all communication is done through the control application. And the latter, after all, of his own devising - JPLAY is popular with many production companies, editors and magazines, to cite, for example, Japan's “Stereo Sound”. If it goes well, it will also be the basis for the work of “High Fidelity.”

At the heart of the S1 was the ZENA platform, and nothing has changed in this regard. It is the world's first motherboard based only on linear voltage regulators. As Marcin said in an interview accompanying the S1 test, other manufacturers, even if they use a linear power supply somewhere, still put switching power supplies on the motherboard. The signal is processed in a 1.6 GHz Quad-Core processor, which was selected “for its high performance in networking applications” and “relatively low power consumption.”

The OCXO Stratum 3E clock, previously proven in JCAT's flagship USB and NET cards, was responsible for clocking in the S1. The S1 Evo uses an even better clock, located on a separate board bolted to the side panel. The manufacturer's website reads:

The Master OCXO Clock in the XACT S1 EVO represents a significant upgrade in digital audio performance, drawing on advanced clock technology similar to that found in high-end audio clocking systems. This clock module is entirely developed in-house, emphasizing precision and stability, which are critical for achieving exceptional sound quality. The result is a digital audio playback that captures every nuance with remarkable clarity.

⸜ → S1 Evo, XACT.audio, accessed: 27.01.2025.

On the motherboard there are three USB ports, two of which are for connecting a USB DAC - one main and an optional one with a 5V power cut. The third USB port is for connecting a FLASH-type memory stick with files. For communications, there are six Gigabit Ethernet ports. There is also a SATA port on the board for connecting an internal drive for music storage. The drive connects to the system via the new Phantom cable that Marcin mentioned above.

The operating system loads from an SD-type memory card. The card also shapes the sound of the transport, although it can be removed after the system is loaded. The operating system was prepared specifically for the ZENA platform, optimized and tuned by Marcin, in his home system. The transport comes with the JPLAY app for iOS, which was developed in parallel. The app is not free, but owners of the XACT S1 Evo get it included in the price of the device.

The manufacturer highlights the high-end components and parts it uses, such as Muse capacitors, top audio components from Japanese company Nichicon, and an IEC socket from Furutech. The power supply is fully linear, stabilized, and is a version of the JCAT Optimo X1 power supply with mains ripple suppression capacitors of total capacity of 140,000 μF.

▌ SOUND

HOW WE LISTENED • The XACT S1 Evo audio file transport stood on a Finite Elemente Pagode Edition Mk II rack, on its carbon fiber braided top shelf. The signal was decoded in the D/A converter section of the Ayon Audio CD-35 HF Edition SACD player. I also used a Lumin T3 file player for comparison. I ran the signal to the player via Acoustic Revive USB-1.0PL Triple-C cable; test → HERE.

With the router, the transport 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. It was connected to the XACT switch via Acoustic Revive LAN Quadrant Triple-C cable with the same company's RLI-1GB Triple-C filter (test → HERE).

⸜ RECORDINGS USED FOR THE TEST ⸜ a selection

⸜ DOMINIC MILLER & NEIL STACEY, New Dawn, Naim naimcd066, CD (2002) & rip WAV z CD.
⸜ ELLA FITZGERALD, LOUIS ARMSTRONG, Ella And Louis Again, Verve Records/UMG Recordings UCGQ-9055, „Acoustic Sounds SACD Series”, SHM-SACD (1957/2024) & rip dsf z SACD.
⸜ SARAH VAUGHAN, Sarah Vaughan Feat. Clifford Brown, EmArcy/UMG Recordings UCGQ-9053, „Acoustic Sounds SACD Series”, SHM-SACD (1955/2024) & rip dsf z SACD.
⸜ KEITH JARRETT, The Köln Concert, ECM Records/Tower Records PROZ-1087, „ECM SA-CD Hybrid Selection”, SACD/CD (1975/2017).
⸜ CHARLIE HADEN & PAT METHENY, Beyond The Missouri Sky (Short Stories), Verve Records | Decca Records France/Universal Classic & Jazz (Japan) UCCU-45054, UHQCD (1997/2022).
⸜ MAŁY ESZ, Bez zabezpieczeń, Aloha Entertainment/Tidal, FLAC 16/44,1 (2025).
⸜ WARHAUS, Karaoke Moon, Play It Again Sam/Tidal, FLAC 24/44,1 (2024).

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I DID NOT put the S1 and S1 Evo versions side by side, so this will not be a direct comparison. However, I am basing this on memory and notes of the differences I heard during the S1 test - differences between files and CDs and SACDs. From what I hear, and I think I hear it clearly, the new player is an evolution of the S1 sound, not a revolution. I don't know if I'm reading the decisions behind the changes correctly, but if so, it would be an evolution of the sound of the first XACT transport in the direction of opening up the sound. To a point, as it's still the sound I liked the original device so much for, but still.

The S1 Evo plays with a lower midrange-based sound. This is the thing that brings it close to the sound of most turntables and the Sforzato DSP-07EX and Lumin T3 file players. It doesn't “muddy” it up, however, because, for example, the trumpet entering in the fourth minute of 5 Autumn in New York, a track from ELLA FITZGERALD and LOUIS ARMSTRONG's album Ella And Louis Again, was strong, crisp, and energetic. The trumpeter's vocals were scratchy with a softly emphasized “throat,” just as I know it from the album. In contrast, the sound of Fitzgerald's voice was deep and soft.

It is a transport that slightly approximates the foreground and deepens the bass. The two go head to head in it, assisting and supporting each other. The guitars of Neil Stacey and Dominic Miller from the New Dawn album in ˻ 3 ˺ El Fado were thus “boosted”. The intelligibility was excellent and only a comparison with the original, CD (the file came from a rip of the CD) showed that the CD transport in the player presented them in a slightly more open way. It also ran the reverberations running far to the rear of the stage more deeply. But these were not differences clearly favoring the silver disc, because what the XACT showed was very immersive. It's rare, but it was a less “analytical” sound, and more “intuitive.”

There is also something in the sound of the XACT file transport, which gives the whole thing energy. I'm talking about the thing that in its predecessor, the S1, was a bit put out, making the sound go in the direction of pleasant, stress-free playing. It was great, it was high-end, but nevertheless clearly characterized by calmness. The Evo version seems more energetic, more “forward”. As if it wanted to excite us more strongly, to set off endorphins in us, to show us that music, is not only melody, but also rhythm, and power.

Thus, in the sound of the tested device, something draws attention, which is rarely seen in such a combination in devices related to file playback: a combination of warmth and energy. Looking at the device with a cool eye, one can say that this is still not the resolution I get from CDs and SACDs. It was the same with the S1 as well. But now this difference seems much smaller. I know it's “there,” which can be heard in the slightly rounded attack of sounds, in the rounding of their decay. But even though it is there it has little “weight”.

And that's because we get at the same time a sound fill that even the Ayon player can't drive this deep. Shock? Maybe not so much, but a surprise and respect flowing out of the understanding of this change - by all means. Pat Metheny's guitar from ˻ 2 ˺ Our Spanish Love Song, a track included on the Beyond The Misouri Sky (Short Stories) album, ripped from the Japanese UHQCD release, had the density and warmth that these recordings are all about. Haden's double bass, heavily emphasized by the sound engineer and deepened, a bit “mellow,” this mellowness deepening was shown with care and with celebration.

These features are even more palpable when you listen to this transport excluding the reference point. As I say, the level of the S1 Evo is similar to the SACD transport in the Ayon CD-35 HF Edition, in general terms, except for resolution. However, when we simply listen to music with it, the characteristics I'm talking about take shape. They are clear beforehand, even quite strongly (it's a transport that has a distinct “personality”), but nevertheless we have somewhere in the back of our minds that the CD transport too shows something else, something extra, so that we can't fully appreciate it. And it's worth it.

Because when we immerse ourselves in this sound, we get a full, dense, finished picture of the musical event. Finished in the sense that nothing is missing in it. There is a deep stage, there is selectivity, and there is resolution. Dynamics are excellent and the powerful drum beats of Philly Joe Jones in the middle of the fourth minute of ˻ 1 ˺ Minority, the opening track of the BILL EVANS TRIO album Everybody Digs Bill Evans, are perfectly energetic and clear. But they are also anchored by a large and dense soundstage.

We will also appreciate this transport for its wonderful bass presentation. The just-released LITTLE ESZ album titled Bez zabezpieczeń begins with ˻ 1 ˺ Intro, in which fantastic, simply exceptional bass is recorded. And this seems to remain in us after “reading” this device. File players shouldn't play in such a cool way, so full and dense. Admittedly, the Taiko Audio Olympus XDMI file transport plays in a much more resolving way, more accurate and clear, but it's still in a class of its own and can compete with the best signal sources on the market, and even with tape recorders and tape. And the S1 Evo also plays superbly, but more “in its own way.”

And this “own” sound is what I want in my system and what I think is right. That is, not at all the most open and selective in the world, nor the most ultra-dynamic and explosive. But one in which there is emotion and which allows me to listen to an entire album without tiring me out after just a few minutes. XACT is exactly that. The dense, pulsating sound of ˻ 6 ˺ Zero One Code, a track from WARHAUS's Karaoke Moon album, thus got a bonus from it in the form of a refinement of the lower midrange and a slight withdrawal of its upper part. These adjustments aren't big, it's more of a tilt than a jump, but they're what make the sound so big, so massive, and so non-fatiguing.

▌ Summary

AND WE'RE STILL TALKING about resolving and open playing. On the day I began listening, exactly twelve hours later and fifty years earlier, KEITH JARRETT began his concert in Cologne. A concert that had no right to take place and in which the musician showed the genius of improvisation on an instrument that was not even worth playing in the back room. And Martin Wieland, recording this performance on a small hand-held tape recorder for documentary purposes only, proved that it's the talent that counts, not the amount of equipment.

I bring this album up because it is the perfect vehicle for the idea that the XACT S1 Evo elevates to an art form: everything, everywhere, now - but only as much as needed, when needed, and in a moment that will not kill us, but enhance us. It's a device that plays in a warm way, more midrange than treble, that's one thing. But also open and resonant, that's another. That is - it's darker, it's warmer, but not at all less energetic. And then there's that bass... It's fantastic in its depth and energy, as well as its draw. Slightly soft, it nevertheless has a well-drawn contour, and is also fast.

Any way you look at it, Marcin Ostapowicz's new transport is a great intermediary between us and audio files. It does it in its own way, though. And it does it in an endearing way, as if it were tailored to our and only our needs. ●

▌ Technical specifications (according to the manufacturer):

Supports: native DSD up to DSD512 & PCM up to 768 kHz, 16-32 bits
Supported file types:
• DSD: dsf, dff
• PCM: FLAC, Apple Lossless (ALAC), WAV, AIFF
• Lossy: MP3, AAC (M4A)
• MQA (passthrough)
Digital outputs
• 2x USB: native up to DSD512 | PCM 44.1-768 kHz, 16-32 bits
LAN inputs: 6x Gigabit Ethernet
SD slot for operating system
Supported streaming services: TIDAL and Qobuz
Reads files from build-in SATA drive, via USB and from local network using UPnP/DLNA protocols
Control app: JPLAY for iOS
Dimensions (WxDxH): 439 x 315 x 100 mm
Weight: 10 kg

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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