A few years ago, I fell in with a bad audiophile crowd -- hardcore computer-audio enthusiasts who ran high-end DIY music servers. Using up to three component cases, these servers featured specially made or modified parts and performance-enhancing software like AudiophileOptimizer, Bughead Emperor, and Fidelizer.

What many of these complex servers had in common was their use of the Windows-based audio player JPlay -- an interesting fact, given the many software audio players out there. Eventually, I migrated through several other players to JPlay -- I appreciated its minimalist interface and single-minded devotion to sound quality.

JPlay is not only an audio player; it’s also a computer-audio company founded in 2010 by Marcin Ostapowicz and Josef Piri, who respectively live in Poland and the Netherlands. Rabid computer-audio enthusiasts who were unhappy with the audio players then in use, Ostapowicz and Piri met on an Internet audio forum, and joined forces to come up with something they felt was better.

As JPlay took off, Ostapowicz branched out, creating a sub-brand, JPlay Computer Audio Transport (JCAT), dedicated to computer-audio hardware. In 2013, JCAT introduced its USB cable. I bought one and found that, in terms of sound quality, it rubbed shoulders with the best USB links out there, including some very expensive ones. Thereafter, JCAT released a slew of high-end computer-audio accessories, including LAN and SATA cables, a USB card, a linear power supply, an OCXO SATA-CF adapter (which allows a compact flash card to be inserted into a standard SATA controller), and an Ethernet switch.

JCAT USB Isolator

When Ostapowicz asked me to review JCAT’s USB Card (€397, or about $421 USD) and USB Isolator (€365 or ca. $384), I was on board.


Designed to work with Windows- and Linux-based USB DACs and USB-to-S/PDIF converters, the JCAT USB Card was created through a partnership with JCAT and Canada’s Adnaco Technology, the latter a designer of products for home computers, marine radar, precision industrial measurement systems, data-acquisition systems, telecom test gear, and medical devices. It features ultra-low-noise, high-precision linear regulators and an ultra-low-phase-noise oscillator, each designed to improve sound quality.

JCAT USB Card Femto

The JCAT card has two high-speed USB 3.0 output connectors and requires 5V of power, to be supplied by a PC’s internal power supply or, via the card’s power jack, by an external power supply. It contains two passive EMI filters at each USB output.

JCAT USB Isolator

The JCAT USB Isolator rejects computer-based noise by providing full galvanic isolation to the USB bus up to 2.5kV, and regenerates, repacketizes, and reclocks the incoming USB computer signal. The product’s technology was not originally developed for audiophiles, but for industrial, measurement, broadcast, and other applications that require stable, high-quality USB signals.

The JCAT USB Isolator’s active internal component is a circuit based on a field-programmable gate array (FPGA) sourced from Intona Technology GmbH, a German company that recently made a big splash with several versions of its own USB isolator. The JCAT features the same printed-circuit board found in Intona’s most expensive and highest-performing isolator, the Industrial Version ($348 including shipping).

Unlike the Intona, however, which has a plastic housing, the JCAT USB Isolator comes in a case of brushed aluminum measuring 5 1/8”W x 1 1/8”H x 2 1/2”D. Ostapowicz states that the aluminum case acts as a shield against harmful electromagnetic interference (EMI) and radio-frequency interference (RFI), thus further minimizing noise. It also has a very upscale look, and sits on four small rubber feet.

JCAT USB Isolator

Galvanic isolation eliminates any electrical connection between two circuits, instead employing other ways to transmit signals: optical, magnetic, capacitive, etc. One very common connection method, often used to prevent damaging electrical surges in household and industrial devices, is through the use of an optocoupler, which uses light to transfer signals between electronically isolated circuits.

To isolate the music server from rest of an audio system, the JCAT Isolator uses complementary metal-oxide-semiconductor (CMOS) digital high-speed galvanic isolators made by Silicon Labs, in Texas. These low-power isolators operate somewhat similarly to optocouplers, except that the circuits are connected through high-frequency radio transmission instead of light. Of course, the goal is to prevent performance-killing noise from entering your audio system.

The JCAT USB Isolator works with USB DACs and USB DDCs (the latter convert USB to S/PDIF or AES/EBU), Windows or Mac computers, and such USB-output-equipped network players as those made by Auralic, Aurender, and Lumin. The Isolator is plug-and-play, requiring neither drivers nor an external power supply.

Computer geek not required

My Windows 10 desktop computer uses the JPlay audio player in JPlayStreamer mode (JPlay’s own implementation of the OpenHome standard) with Linn’s Kazoo file-management app. Despite the fact that the JCAT USB Card is often used in complex state-of-the-art servers, installing it in my computer was a snap: I opened the computer’s case and slipped the card into one of its PCI-e slots.

For a 5V power source, I used an iFi Audio iPower wall-wart adapter. At $49, the iPowers sound better than the cheap, ubiquitous wall warts found throughout most homes. An even better solution would likely be JCAT’s own aluminum-cased, 100W linear power supply (€340 or about $356), made from high-quality parts and featuring dual 5V outputs that can power a USB card and two solid-state drives.

Having installed the card, I turned on the computer, which automatically downloaded Microsoft’s USB 3.0 PCI-e host controller driver. Because the card uses the NEC uDP720201 USB controller chip, the Renesas USB 3.0 host controller driver (with which some have had excellent results) can be used instead of the default Microsoft driver.

Lastly, I connected my Esoteric K-01X SACD/CD player-DAC to one of the card’s USB ports, and to the other an external hard drive filled with music.

At first I used the JCAT USB Isolator in a relatively modest system consisting of a Windows 10 laptop, M2Tech Evo DAC Two Plus, and System Audio Saxo 5 active speakers. But using the JCAT in my big rig also brought sonic differences and allowed me to use the Isolator with the JCAT USB card, so that’s where I did my review listening.

Setting up the JCAT USB Isolator, too, was easy. I connected one USB cable from the Isolator’s Type-A connector to the K-01X, and a second USB cable from the Isolator’s Type-B connector to my desktop. The Isolator’s connectors securely gripped each USB cable -- a reassuring sign.

I mostly used the Isolator with one of two excellent audiophile USB cables: the JCAT (€499 or ca. $523) and Synergistic Research’s Galileo LE ($1995). However, in theory, since the Isolator regenerates, repacketizes, and reclocks the USB signal, the quality of the cable from my computer into the Isolator might not be critical. I therefore also experimented by running either a Belkin Gold USB cable ($8) or a generic, 32’, active USB extension cord ($18) into the Isolator.

You may want to bypass the Isolator’s rubber feet by using a set of good aftermarket footers. I had excellent results both with Symposium’s RollerBlocks and Synergistic Research’s MIG footers. The Isolator weighs less than half a pound -- slightly more than the Intona Industrial Version -- due to its aluminum case. The relatively flexible USB cables didn’t overly restrict the Isolator’s placement or prevent it from securely resting on the footers.

I listened to digital music files from my external USB drive and streamed from Tidal, taking advantage of the latter’s Masters option, which permits the streaming not only of lossless 16-bit/44.1kHz FLAC files, but also of MQA-encoded files of higher resolutions. Streaming Tidal through JPlayStreamer is said to improve Tidal’s sound. Currently, however, that can be done only through the BubbleDS control-point app installed on an Android device. Therefore, I directly streamed Tidal through its Windows PC app.

JCAT USB Isolator

Both the Card and Isolator sounded a bit closed-in at first, but this disappeared after a bit of run-in.

One more thing: A few weekends ago, I was invited by James West, of Adirondack Audio & Video, to hear Technics’ new SB-R1 speakers at the company’s Manhattan showroom. In the signal chain was a Hegel Music Systems HD12 DAC. I’d brought along the JCAT USB Isolator to try it in that system, but we couldn’t get it to work. No sound. Nothing.

Hegel subsequently confirmed that the HD12’s USB chipset doesn’t work with USB regenerators. Owners of Hegel DACs are advised to check with Hegel to determine whether their units have a regenerator-compatible chipset. Ostapowicz states that this is the only time that he’s heard of such an incompatibility; sure enough, the JCAT Isolator worked flawlessly with both my Esoteric and M2Tech DACs.

I’m not used to being carded at my age. Isolated, yes. Carded, no.

Used individually or together, the JCAT USB Card and USB Isolator improved virtually every aspect of the sound. The noise floor was lowered, and resolution was enhanced. In general, things seemed more relaxed and less, well, “digital.” Transient impact improved, and the sound was more transparent. Soundstages were higher, wider, and deeper, and imaging and focus improved. Within soundstages, voices and instruments had more focus and weight. There was less distortion and glare on high-frequency peaks, and the midrange, including voices, was cleaner and richer. Bass was firmer and better defined.

The JCATs thrived on digital downloads of well-recorded music. In Billy Cobham’s often subtle drum solo in “Anxiety/Taurian Matador,” from his Spectrum (24-bit/96kHz FLAC, Rhino), the prominent snare drum was now concretely placed at center stage. I could viscerally feel the initial impact and flutter of the hard-struck drum skins, and the subsequent decays were much longer and more detailed. Jan Hammer and Tommy Bolin’s duet on, respectively, Moog and guitar was now much more present and involving.

“Have a Cigar,” from Pink Floyd’s Wish You Were Here (16/44.1 FLAC, Columbia), segues into the title track with the sound of an old-style analog radio tuner being dialed through several stations, including one broadcasting the fourth movement of Tchaikovsky’s Symphony No.4. Even in this brief linking segment -- a recording of the radio in David Gilmore’s car, in the parking lot of EMI’s Abbey Road Studios -- it was apparent that the JPlay products were making possible wider, deeper soundstages and more detail -- even the interstation static was crisper and better articulated.

Due to its slide, the trombone has the greatest range of notes of all brass instruments. This was beautifully demonstrated by Charles Mingus’s Mingus Ah Um (DSD64, Columbia/Legacy), the second part of which is full of trombone melodies and solos. The JCATs nicely exposed the sometimes subtle note changes in these passages. While I’ve heard greater timbral definition with some very-high-end servers, the JCATs weren’t at all shabby in this regard, and eons better than the sound without them.

In Diana Krall’s cover of Joni Mitchell’s “A Case of You,” from Krall’s Doing All Right (16/44.1 FLAC, IMC Music Limited), her brooding voice was now more textured, the background “blacker,” the attacks of her piano notes cleaner and more penetrating.

The JCATs also improved the sound of files streamed from the Internet. For me, streaming, including Tidal HiFi’s streams of MQA-encoded files, has never matched the sound of a good CD or download. Ostapowicz states that this is because such streaming, as opposed to streaming within a home network via a wired LAN, entails the simultaneous downloading and playback of the file, thus potentially causing audible problems of data latency even when the incoming data packets are first cached. When I stream Winter, from Vivaldi’s The Four Seasons (16/44.1 FLAC, Infinity Digital/Tidal), the harpsichord can be overshadowed by one of the violins. The harpsichord, which has a far more delicate sound than the piano, fell out of favor after 1768, when Johann Christian Bach gave the first London piano recital. However, with Tidal streamed through the JCATs, the harpsichord in the Vivaldi was presented with more presence and elegance.

In “Safe (Canon Song),” from the late Chris Squire’s Fish Out of Water (16/44.1 FLAC, Atlantic Arc/Tidal), the notes Squire plays on the four-string bass section of his double-necked guitar weren’t as well delineated via streaming as they were from a CD (Japanese CD, Atlantic). Surprisingly, however, the bells were fairly well articulated, with air and attack.

In “Bitter Kitten,” from deadmau5’s At Play, Vol.5 (16/44.1 FLAC, Play/Tidal), the synthesized bass beat via Tidal was, for the first time, punchy enough to take fair advantage of my JL Audio Fathom f113 v2 subwoofers’ impressive abilities, even if significant portions of detail and transient thrust were still not as well presented as when I listened to a ripped download of this track through JPlay and the JCATs.

Despite streaming’s current sonic failings (which are no fault of the JCATs), the JCATs imbued Tidal’s sound quality with many hallmarks of audiophile-grade sound. This made streaming more enjoyable, and prompted me to dig deeper into Tidal’s catalog. Overall, I was surprised by how much of the quality of a high-end server the JCATs provided. While the use of a USB connection for the high-quality reproduction of music has its detractors, these products reinforced my belief that, as with many of audio’s other technological battles (e.g., vinyl vs. CD, tubes vs. solid state), it’s all about the implementation. Indeed, Ostapowicz told me that, in terms of sound quality, it’s the computer, not the USB protocol, that’s the problem. Fix the computer, he said, and you can get sound over USB that is nothing short of stunning.

The JCAT USB Card and USB Isolator are excellent values. Including my desktop computer ($500), JPlay (€99 or about $104), and the JCATs (about $805), the total cost of my computer-audio system is a little over $1400. There are only a few full-size music servers that cost that little. There’s one school of thought in the DIY community -- undoubtedly disputed by many high-end audio manufacturers -- that spending megabucks on a preassembled music server, which in many instances is essentially a modified computer, is a waste of money.

But adding a USB card and galvanic isolator to a stock PC does not a world-class music server make. It is for that reason, as noted above, that numerous other hardware upgrades are available from JCAT. With the exception of the OCXO SATA-CF adapter, each of these can be installed by someone with little technical knowledge.

Finally, to satisfy my curiosity about the USB Isolator’s cable requirements, I ran my Belkin Gold USB link ($8) from my computer to the Isolator’s input, instead of one of the expensive audiophile cables. Doing so didn’t substantially affect the sound, so I added to it a 32’-long generic USB extension cord ($18), also without meaningful degradation of the sound. This allowed me to position my computer far from my stereo system.

Using the Belkin link to connect the Isolator’s output to the DAC was a different story. The differences in sound compared to the JCAT and Synergistic Research’s Galileo LE cables were now quite noticeable, and not positive. The Belkin, while sounding stunning for less than a sawbuck, couldn’t approach the sound quality of either audiophile cable.

I know what you’re thinking: Might using the USB Isolator make the quality of the music server far less important? Some people, including some respected folks in the industry, believe that nothing in the signal chain before the regenerator affects the sound quality. However, my experience has been that, even with a regenerator, everything on the server side, including the software and hardware, still matters, to greater or lesser degrees. This was confirmed when I removed the JCAT USB Card from my PC -- despite the USB Isolator’s continued presence, the sound quality deteriorated: a testament to the Card’s abilities.

From novice to expert

JCAT’s USB Card and USB Isolator are often used by hardcore computer audiophiles who run expensive and devilishly complex state-of-the-art music servers. Nonetheless, I found these products a cinch to install; they should appeal to computer novices who just want their computer-audio systems to sound better. Whether your system costs $1000 or $100,000, you’re likely to find that the JPlay JCATs help it do just that.

. . . Howard Kneller

Associated Equipment

  • Amplifier -- Esoteric A-03
  • Preamplifier -- Esoteric C-02X
  • Sources -- Desktop computer running Windows 10, JPlay; Esoteric K-01X SACD/CD player, Stanford Research PERF10 Rubidium Clock; M2Tech Evo DAC Two Plus DAC
  • Other electronics -- JL Audio CR-1 active subwoofer crossover
  • Speakers -- YG Acoustics Kipod II Signature
  • Subwoofers -- JL Audio Fathom f113 v2 (2)
  • Interconnects -- Synergistic Research Atmosphere Level 4
  • Digital cables -- JPlay JCAT USB, Synergistic Research Galileo LE USB
  • Speaker cables -- Synergistic Research Atmosphere Level 4
  • Power cords -- Synergistic Research Atmosphere Level 3
  • Power conditioners and distribution -- Synergistic Research PowerCell 12 UEF SE and QLS power strips
  • Isolation devices -- Symposium Acoustics: Osiris Ultimate and Standard Racks, Segue Platform, RollerBlock Series 2+ Equipment Support System; Synergistic Research: Tranquility Bases, Silent Running Audio VR fp Isobase, MIG 2.0s footers
  • Room treatments and correction -- Synergistic Research: Acoustic Art System, HFT and FEQ room-treatment devices
  • Misc. -- Synergistic Research Grounding Block, Mad Scientist Black Discus Audio System Enhancer, WA-Quantum Quantum-Sound-Animator, Hi Fidelity MC-0.5 Magnetic Wave Guides

JPlay USB Card
Price: €397 (ca. $421 USD).
JPlay USB Isolator
Price: €365 (ca. $384 USD).
Warranty: NA.

Rymarska 45/1
53-206 Wrocław

E-mail: support@jplay.eu
Website: www.jplay.eu