Review Jcat NET CARD XE – Optimo 3 Duo – Clean Stream


  • It just works! Works directly on almost all systems
  • Internal and external power supply


  • Pricey upgrade
  • Installation not for everyone
  • Price: € 800

    Build quality



    It has been quite a few years since we tested the first “audiophile” plug-in card. At the time we did have our doubts, to be honest, because data is data right? Yes… that is certainly true. But now we know better. It’s not about the data, but about how clean that data comes in. Free from crap like common mode noise. Jcat is one of the bigger players that understands this. We take a look at the new Jcat NET CARD XE and the Optimo 3 Duo power supply. We also have a USB XE plug-in card, but that review will be published later.
    The protocol that most of a network – and the Internet – runs on is called TCP/IP. This protocol is decades old and incredibly robust. With TCP, error recognition and correction is built in. In short: data errors theoretically just don’t happen. And we haven’t measured them on our network either. Unless we cut a cable in two, for example. And that makes sense.

    The other major protocol – UDP – works a little differently. The UDP protocol has error recognition built in, but no error correction. The reason is simple: latency. In video calling, for example, it is inconvenient if delays occur. It is not so bad if we have a glitch somewhere, but we can continue our conversation. Theoretically, data could be lost. And yes: that does happen, but less than you would think.

    Common Mode

    A network is quite a robust entity. For the normal functioning of a data network in your home, you do not need high-end stuff. A midrange router with a decent switch is enough to enjoy the internet and Netflix. And your audio streamer will be fine too.

    So why all this high-end stuff in our little audio world? Is that really necessary? Well… in a way, yes. Unfortunately. Although switches are already filtered pretty well (via galvanic decouplers), some noise gets through. Particularly through noisy power supplies, we measured. There is just common mode noise measurable. And a good switch removes that, potentially making your system sound better.

    Now that – we estimate – also works with a network card. Those who want to make their own (high-end) streamer (and yes: that’s cool!), can of course start with the onboard network port. And usb port. But we have very quickly found that in any case a separate usb card is recommended. A separate network card idem. For the same reasons that a good power supply on a switch gives audibly better results.

    Jcat NET Card XE

    Jcat has pulled out all the stops for the Jcat NET Card XE – €800 – an ultra-quiet power supply, tight clocking, better network ports and, of course, the ability to power externally for an even lower noise floor.

    The controller comes from Intel: the i350 gigabit chipset. The nice thing about the Intel controller, is that it works plug and play almost anywhere. Our ROON (Roon Rock) server recognizes it immediately after a reboot, so we can get started right away without having to go to the command line for driver packages.

    Jcat Optimo 3 Duo

    In addition to the Jcat NET Card XE, we also have the Optimo 3 Duo power supply. This provides 2 x 5 volts with 3 amps. Sufficient for our Jcat Femto network card and Usb card. Previously we used Sboosters on it and that also works great. Audibly better than feeding internally (more calmness). The Optimo 3 Duo costs €1500, which is of course considerably more than two Sboosters. In short: the question for us is: is it better than the Sbooster and is it worth the extra investment?

    Internally, the Jcat has a large toroidal core and a large buffer stage to smooth everything out. Clearly designed to get the absolute maximum out of a system. This power supply can of course handle anything that uses 5 volts and up to 3 amps. Think of a high-end switch, dac that works at 5 volts, et cetera. This seems a bit overkill for a network and usb card to us honestly. Anyway.


    What the new Jcat NET Card XE and Optimo Duo are supposed to bring is more calmness, more resolution and more insight into the playback. Purely by keeping electrical noise – common mode – ultra-low. By the way, forget those fables about tighter clocking of a network; it does nothing. A network’s clock is independent of the clock in a d/a converter or other digital audio source. The only thing that theoretically could be improved, is phase-noise from the clock. However, the clock would have to be immensly bad, which seems odd to us.


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