Master OCXO Module with USB XE Card
Master OCXO Module
Master OCXO Module with RF cable
Master OCXO Module with RF cable 2
Master OCXO Module RF cable
Master OCXO Module with USB XE Card
Master OCXO Module with USB XE CardMaster OCXO ModuleMaster OCXO Module with RF cableMaster OCXO Module with RF cable 2Master OCXO Module RF cableMaster OCXO Module with USB XE Card

Master OCXO Clock Upgrade


Experience an unprecedented level of musical excitement thanks to JCAT’s first-ever in-house developed OCXO (Oven-Controlled Crystal Oscillator) Master Clock Generator.

Free worldwide door-to-door upgrade service for USB XE owners included!


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Can we help you? Our Customer Service will be happy to assist you with your requests.

Unlock the full potential of your JCAT USB XE card and elevate its performance to the absolute pinnacle with the Master OCXO upgrade. 

Our Master OCXO Upgrade isn’t just an enhancement; it’s a true transformation of sound quality. The clock’s low noise and exceptional stability bring purity and precision to your audio system.


High-Precision Master Clock Generator.

JCAT’s first-ever in-house developed high-precision ultra-low noise OCXO (Oven-Controlled Crystal Oscillator) Master Clock Generator replaces onboard clock oscillator on the USB Card XE. The exceptional characteristics of the Master OCXO Clock Module deliver a realistic and refined sound quality beyond your wildest dreams.


No-Compromise Expert Design.

The Master OCXO Clock board and the included RF clock cable were designed in collaboration with a specialist in radiophysics who provided invaluable insights ensuring that every technical aspect was carefully considered. By focusing on the most subtle nuances, JCAT has attained an unparalleled level of musical playback quality within the realm of digital audio.

Superior OPTIMO Power.

The power supply section on the Master OCXO Clock module derives its excellence from the distinguished OPTIMO series truly-linear power supplies. It features two separate power phases for the Oven-Controlled Crystal Oscillator and for the clock output buffer guaranteeing peak performance while minimizing unwanted interference.

Luxurious Audio Commponents.

The Master OCXO board is meticulously gold-plated, fitted with premium audio components ensuring top-quality connections and reliability for years.

The ultimate and the best upgrade for your USB Card

While the OCXO found on USB & NET XE cards is already of exceptional quality, opting to upgrade to the Master OCXO instantaneously elevate your digital frontend to a level akin to possessing a higher-class DAC. Invest in the Master OCXO Upgrade and experience the difference in sound quality that will take your audiophile experience to an entirely new level. The price includes free worldwide door-to-door upgrade service; the customer will receive a pre-paid UPS Express return label for his USB Card XE, the card will be upgraded at our factory in Poland and the customer will receive upgraded USB Card XE with the Master OCXO as pictured below. The successor of the USB Card XE – the USB Card XE EVO – can accept the Master OCXO Clock without any modifications! 

Master OCXO Clock Upgrade with the USB XE Card


Master OCXO scheme

DC barrel plug 5.5/2.5 power connector, center positive, connect 5V 1A power supply here.

HDD type power connector 5V only, connect PC power supply HDD connector here.

Power OK LED indicator, this illuminates when Master OCXO module successfully powers up.

OCXO oscillator

Clock output 1 female SMA connector.

Clock output 2 female SMA connector.


  • DC supply voltage5 ± 5% V
    Power consumption4.5 W (during warm-up)
    1.5 W (steady typ.)
    Max input current900 mA
    DC input connectors5.5/2.5 DC barrel
    LP4 Molex
    Standard operating temperature0 to +40 °C
    Storage temperature-40 to +85 °C
    RF output frequency20 MHz *
    Output impedance (unbalanced)50 Ω
    RF output voltage (at 50Ω load)2.2 Vpp
    RF output typeCMOS
    Clock outputs2x SMA
    RF cable6G
    50 Ω
    200 mm length
    Warm up time (typ. @25 °C)5 min.
    Phase noise<-135 dBc/Hz @ 100Hz offset typ.
    Frequency stability± 5 ppb
    Dimensions86 x 49 x 23 mm
    Weight90 g
      • * other frequencies available on request
      ** custom connectors available on request


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‘It transformed my system from a “stereo” playing music to bringing me much closer to a real musical performance..’rob dockery, stereo times


‘Over all the years every new JPLAY/JCAT  gear, every upgrade, meant a significant step forward in my system, but when they announced an upgrade for the USB XE card my expectations where not that enthusiastic, to be honest. To my ears it was already perfect.


You can make everything sound different, but better? This-or-that-improvements, better highs, bass, whatever, which only get on your nerves after while. I never had this with jplay/Jcat and – to make it short – they did it again, promise kept.


This upgrade again brings your stereo one important step up on the stairway to high-end-heaven and brings us listeners another step closer to the recording room. This is how it has to be!

hans-peter, germany


I sent my USB card to JCAT. After a fast, first-class service, I received the “upgrade” parts in return. I’ve now been using it for less than a week and I’m sure I’ll never go back. The sound is wonderful: more body, more definition, more texture “from bass to treble”.
Christian, switzerland


How can I perform the upgrade? (USB Card XE only. The New USB Card XE EVO can accept the clock without modifications)

We will do everything for you, free of charge. When purchasing the Master OCXO Clock upgrade you will receive a pre-paid UPS Express return label. We’d ask you to pack your USB Card XE and we’ll arrange for UPS courier service to pick up your package. Once it reaches our factory in Poland, your card will be upgraded to accept the clock signal from the Master OCXO module. To achieve this, we’ll install the adapter specifically developed for the XE card that allows you to connect the RF cable in place of the standard oscillator on the card. The prepared and tested card, along with the Master OCXO module and the RF cable for connecting both components, will then be shipped back to you, also through UPS Express shipping service. The entire process, from receiving your card to delivering the upgraded card with the Master OCXO to your doorstep, will take approximately 7 working days.

Is it easy to connect the Master OCXO with the USB Card XE? Do I need any tools?

No tools are required. You will receive the cable with screwed-down SMA connector on the Master OCXO Clock side and a custom click-on connector on the USB Card XE side. Just connect both components together with the supplied cable and that’s it!

What is included in the price? 

1x Master OCXO Board

1x RF clock cable

Free worldwide door-to-door upgrade service (see the details above).

The Master OCXO Upgrade does not include the USB Card XE/EVO! If you would like to purchase The USB Card XE EVO with the Master OCXO Clock Upgrade, please use this product page:

Why should I consider purchasing the upgrade? It is quite expensive.

Although the clock oscillator on the USB XE/EVO card is already very good, the Master OCXO Upgrade brings a VERY significant improvement. It isn’t just an enhancement; it’s a true transformation of sound quality. 

Is a separate power supply required for the Master OCXO board?

Yes, the Master OCXO board requires 5V/1A power supply, either through LP4 molex or 5.5/2.5 barrel connector.


Is there general recommendation how/where should one place his Master OCXO board in the computer?

Place of instalation is limited by length of RF cable. We did not find it matters much. You need to keep in mind that the OCXO oscilator runs quite hot, so it is wise to give it some space. There is self-adhesive tape included to install the Master OCXO in the enclosure and help with RF cable arrangement.

I see there are 2 Clock Output terminals on the Master OCXO, can I use one of them to output the clock signal for the NET Card XE?

The current revision of the NET Card XE runs a different clock frequency, so that won’t work. However, JCAT will release a new version of the NET Card XE in 2024 that will accept the same clock frequency as the USB Card XE/EVO. It will be possible to use a single Master OCXO Board for both cards then, without any performance drawbacks. 

Can I use the Master OCXO with any other components? 

Yes, you can install it as a DIY upgrade kit in a DAC, music server, network switch etc. You can order a different frequency of the Master OCXO; e.g. 10MHz or 25MHz. You can request a different connector for the RF cable (e.g. BNC). This is included in the price. Although the free upgrade service is limited to JCAT cards, so for other components you are buying the Master OCXO Upgrade as a DIY kit. Should you need any assistance please contact us at 

Can I use a single OPTIMO nano PSU to supply both the USB Card XE and the Master OCXO Clock? 

Yes, you can! The OPTIMO nano 2A output current will be sufficient to power both the USB Card XE and the Master OCXO Clock.

Weight0,1 kg
Dimensions9 × 5 × 2 cm

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