Getting started with JPLAY FEMTO

by admin
July 13, 2020


Highest playback quality on a PC, remote app on a tablet

JPLAY FEMTO is a complete network music software player created by fanatical audiophiles for the most demanding audiophiles.

The word ‘network’ does not imply that music files must be streamed over network. In contrary – it means that the best sound quality can be achieved by playing files that are stored directly on a PC which connects to a USB DAC.  Utilising network brings convenience that has not been available in the past with any JPLAY release; sitting relaxed on a couch and controlling playback by a remote app on a tablet or smartphone. Without touching the PC.

Getting started

  1. Download and run JPLAY FEMTO setup on a Windows PC that is connected to your USB DAC. The PC must be connected to Internet and home network’s WiFi. Windows 8 or later is required.

  2. Select the folders with your music files during JPLAY FEMTO setup.

  3. After successful installation restart PC. (this is mandatory)

  4. Make sure you have the latest driver installed for your USB DAC. (The built-in Windows USB Audio Class 2.0 driver is not compatible with JPLAY!)

  5. From Start Menu – Programs – JPLAY, open ‘JPLAY Settings panel’ to select your output device (‘Playing via’ field). By default the output is set to the best sounding playback method, KS (Kernel Streaming).

  6. Open a UPnP remote app on a tablet or smartphone connected to your home network’s WiFi; JPLAY for iOS  is highly recommended! , select JPLAY FEMTO as the renderer and JPLAY femtoServer as the library

  7. Voila! You can now play your music files at the highest possible sound quality.

  8. appmockup

TESTED REMOTE APPS:  Bubble UPnP (Android) mConnect (iOS), Kinsky (Windows, iOS, MacOS)

Buy JPLAY FEMTO or test-drive if for free for the next 21 days! Download FREE TRIAL

SPECIAL OFFER for existing JPLAY customers!

All existing JPLAY customers can upgrade to JPLAY FEMTO at almost half the price -  save 70 EUR!

To buy the upgrade at the special price, please transfer 79 EUR via PayPal to:

(only verified existing JPLAY customers are eligible for this special offer!)

Improve sound quality of streaming with JPLAY FEMTO

JPLAY FEMTO supports both files stored locally on a hard drive and music files in the cloud; online lossless music services such as TIDAL & Qobuz (including hi-rez Qobuz Sublime plan).

No extra configuration is required to benefit from JPLAY FEMTO’s unique sound quality also when streaming music from the cloud. You just have to log in to your TIDAL or Qobuz account in a remote app.,

Below are the screenshots showing TIDAL in : Bubble UPnP (Android) and mConnect (iOS). 0


Bubble UPnP on AndroidScreenshot_20200713-141229 Screenshot_20200713-141257 Screenshot_20200713-141308 Screenshot_20200713-141312 Screenshot_20200713-141442 Screenshot_20200713-141458 Screenshot_20200713-141539 Screenshot_20200713-141558

mConnnect on iOS
IMG-0691 IMG-0690 IMG-0695 IMG-0692 IMG-0693 IMG-0694

Spotify Connect

Thanks to HIFY app on Android it is possible to select JPLAY FEMTO as output in the official Spotify client.

All you need is an Android device (tablet or smartphone) with running HIFY app


Once the HIFY app is launched, JPLAY FEMTO shows up in any spotify client running in your network – on Android, iOS, MacOS or Windows. Below is a screenshot of the spotify app running on my Macbook Pro. As you can see, JPLAY FEMTO is listed as a ‘spotify connect’ device.


If you have any questions or issues please contact us at or post on our forum here: We are happy to help!


About the author

Marcin Ostapowicz is a recognized high-end audio consultant. Computer audio pioneer. Co-creator of the award-winning software, JPLAY. Manufacturer, curator and distributor of high quality audio products. Constantly strives for perfection of sound. Foundations for his breakthroughs finds in areas that others ignore.


by admin
April 8, 2019

JPLAY will unveil new products at the HIGH END 2019 in Munich.
Our booth is in Hall 2, E01. Please join us and experience the cutting edge computer audio.

JPLAY FEMTO: the new benchmark in digital audio reproduction

by admin
October 29, 2018

A complete network music software player for the most demanding audiophile.

JPLAY FEMTO combines unrivalled digital playback algorithms with convenience that has not been available before.

FolderIcon - 256x256

Now featuring our femtoServer, ultra-light and ultra-optimized UPnP media server, digital files are reproduced with higher transparency and precision than ever before, giving you greater insight into all of your music.

JPLAY FEMTO, our UPnP Renderer, can extract the best performance from virtually all audio formats and resolutions including DSD Native (RAW) up to fs256 & DSD DoP up to fs256.

Thanks to extreme optimizations in JPLAY FEMTO, not only local files sound better – Tidal & Qobuz hi-rez lossless streams can be played at much higher quality too.


  1. Download and run JPLAY FEMTO setup
  2. Select the folders with your music files
  3. Restart PC
  4. Open JPLAY Settings panel to select your DAC
  5. Open a UPnP remote app on any device in your home network (see the list below), select JPLAY FEMTO as the renderer and JPLAY femtoServer as the library


TESTED REMOTE APPS: Kinsky (Windows, iOS, MacOS), Glider (iOS), mConnect (iOS)

->Download NOW<- fully-functional JPLAY FEMTO which also includes JPLAY Classic and test-drive it for free for the next 21 days!

To all customers who ask for JPLAY Classic – the free trial version includes both JPLAY Classic and JPLAY FEMTO, if you don’t wish to upgrade to FEMTO you can ask for a free JPLAY Classic code when JPLAY trial expires
The price for new customers is 149EUR (includes both JPLAY FEMTO & JPLAY Classic) and can be purchased here:

SPECIAL OFFER for existing JPLAY customers!

All existing JPLAY customers can upgrade to JPLAY FEMTO for only 79 EUR!

Please use this PayPal button to purchase the upgrade:

(please note your email has to match the one used when buying JPLAY – only verified existing JPLAY customers are eligible for this special offer)

Main Features:

  • JPLAY FEMTO UPnP renderer converts a PC into a hi-end audio endpoint
  • JPLAY femtoServer UPnP media server converts a PC into a hi-end music server
  • Smallest buffer of any music player (DAC Link 1000Hz)
  • Supported Audio Formats: FLAC, WAV, DSD DoP 64/128/256, DSD Native up to 256 (via ASIO), AIFF, ALAC, M4A, MP3, WMA
  • Supported Streaming Platforms: TIDAL, Qobuz (including Sublime hi-rez plan)
  • Supported Playback Methods: Kernel Streaming (KS), WASAPI Event Style, ASIO
  • Special intel CPU optimized version (user-selectable)
  • Gapless Playback
  • Supported OS: Windows 8 or later (64-bit only)

More details about the features and configuration can be found in our manual here:

If you have any questions or issues please contact us at or post on our forum here: We are happy to help!

JPLAY dual PC mode: how it works & why you need it

by admin
September 27, 2017

The ultimate mode for most demanding audiophiles

The dual PC mode is a configuration where JPLAY is running on 2 PCs in a home network. It offers superior sound quality compared to a setup with just a single PC. Think of a CD integrated player vs. a CD transport + DAC analogy – the latter usually sounds better.

Control PC + Audio PC

One PC can be for general use: web browsing, work, editing photos etc. You run any software player that is compatible with JPLAY and start/stop playback here. You’d usually have your media library (music) here as well. This would be your Control PC. From user’s perspective, it works exactly the same as a single PC setup except that the actual playback happens on a different PC – Audio PC.

Audio PC is a PC that connects to your audio system – a USB DAC or any other audio interface compatible with JPLAY (USB-S/PDIF converter or PCI Express sound card). Audio PC can have nothing else installed apart from JPLAY and USB DAC drivers. It can be headless and you don’t have to touch it at all after initial setup, because all playback related parameters are adjusted from JPLAYSettings panel on Control PC (some advanced settings from regedit).

Both PCs must be in the same network, but do not have to be located in the same room – you can have Control PC in an office and Audio PC close to your audio system in a living room. Control PC does most of playback related processing and streams music bytes over Ethernet to Audio PC which then outputs them directly to a USB DAC or any other supported device.

Because Audio PC needs only a small capacity drive for the operating system, JPLAY and essential drivers, it’s easy to make it compact and noiseless. You just need to pay attention to a power supply and a USB output in case you use a USB DAC – the higher quality, the better sound you will get. The quality of network components and cabling on both PCs is important as well. OK, almost everything can have an effect on playback quality in a computer audio system, but this is a story for another article.


Install JPLAY on both Control PC & Audio PC and restart the PCs. Make sure DAC is connected to Audio PC, switched on and drivers for the DAC are installed.

Open JPLAYSettings panel on Control PC and click on the button next to Audio PC until you see ‘Search my LAN for JPLAY’. Confirm by clicking OK to initiate search.
Few seconds later ‘Found JPLAY on 1 computer’ message should be displayed. Click OK, reopen JPLAYSettings panel, select your Audio PC (IP address) and adjust output parameters. All compatible audio devices connected to your Audio PC will be listed as if they were connected directly to Control PC.

Tips & tricks for best sound

  1. Use JPLAY Hibernate mode. Shuts down almost all Windows processes during playback on Audio PC and ensures highest sound quality.
  2. Use Windows 8 or later on both PCs to access JPLAY’s best playback engine, UltraStream and JPLAYStreamer.
  3. Even better results can be achieved with Windows Server 2012 or 2016. If you have it at least on Audio PC, you can improve sound further by switching to Core mode (manually or via Audiophile Optimizer tool)
  4. Disable power saving features for network adapters and USB ports on both PCs to prevent dropouts.
  5. As ControlPC is doing most of the processing, it should be more powerful than Audio PC (same specification for both PCs is fine too).
  6. Dedicated Audio PC with only JPLAY and DAC drivers on it will sound better than Audio PC that has many applications installed.
  7. Disable JPLAYStreamer service on Audio PC from Control Panel -> Administrative tools -> Services. You need it only on Control PC.
  8. Quality of hardware components and power supplies is important for both PCs – use audio grade components such as JCAT on both PCs and get better sound.
  9. Use wired Ethernet connection. It’s more reliable and will sound better, especially if you use a high quality LAN cable.
  10. Set network connection speed to 1Gbit/s if it’s supported.
  11. High quality network adapter such as JCAT NET Card on both PCs will greatly improve sound.
  12. Use direct LAN cable connection between Control PC & Audio PC (requires setting a static IP at least on Audio PC). If direct connection is not possible, use audio grade network switch between PCs.
  13. Network connection between Control PC and Audio PC should be on a dedicated subnet. E.g. if connection from Control PC to home network is on 192.168.1.x subnet, make sure to set IP addresses for network adapters that connect Control PC & Audio PC to 192.168.2.x. This way traffic for JPLAY dual PC mode is completely isolated from home network.

Example configuration

The example in this section illustrate my configuration of JPLAY dual PC mode.

JPLAY dual PC diagram

I control playback (JPLAYStreamer) from my Macbook most of the time via Linn Kazoo Control Point app. I occasionally use roon to stream TIDAL content – I have roon installed on my Macbook and Roon bridge on Control PC. Roon is set to use JPLAY Driver as output. Note that in this case playback goes through JPLAY dual PC mode and my main stereo too.

I have my music library (Media Server) running directly on Control PC. Sometimes I also use Linn Kazoo or Kinsky Control Point apps directly on Control PC.

JCAT NET Cards FEMTO are installed in both Control PC & Audio PC and connected directly via JCAT Signature LAN Cable (coming soon). The network connection is on different subnet to isolate it from home network traffic.

Audio PC is headless, located near main stereo system. Output goes through JCAT USB Card FEMTO to my USB DAC.

For more information please check our manual, visit our forum or simply send a mail at

About the author

Marcin Ostapowicz is a recognized high-end audio consultant. Computer audio pioneer. Co-creator of the award-winning software, JPLAY. Manufacturer, curator and distributor of high quality audio products. Constantly strives for perfection of sound. Foundations for his breakthroughs finds in areas that others ignore.


by admin
June 26, 2017

1st ever audiophile network interface

With streaming services becoming the primary way of listening to music and with the shift from standalone computer audio setups to network renderers, the quality of network-related components becomes crucial if one wants to enjoy high resolution music at the highest sound quality.

Ethernet adapter for high-end network audio

Setting up a media server on a PC or using a computer as a network audio renderer (endpoint) is easy nowadays. But the problem with computers is that they were never designed with audio in mind. While there are improvements for USB-based playback available (such as our JCAT USB Card FEMTO or JCAT USB Isolator), the network controller part of a PC remains noisy. JCAT delivers the solution with the NET Card FEMTO – the ultimate network interface designed specifically for transferring high-quality audio over LAN.

The most accurate components

By using ultra-low noise linear power supplies and FEMTO Clock Technology combined with high-end Ethernet controller from Intel, the JCAT NET Card FEMTO ensures maximum network transmission quality. Connect a network audio player, a media server (NAS) or a broadband router to any of the two 1Gbit LAN ports on the JCAT NET Card FEMTO and experience great sound quality improvement when streaming audio data.

Exceptional audio quality


The sound image becomes crystal-clear: transparent, quiet, smooth and yet full of fine details you have never heard before. It will allow you to experience music at much deeper level.


You can use the JCAT NET Card FEMTO to improve sound quality of any network audio player (renderer/endpoint/streamer) when streaming audio data from NAS (media server), from music services such as TIDAL, Qobuz, Spotify etc. or directly from PC music server.


JCAT NET Card FEMTO will also enhance playback when installed in an Audio PC – a computer that acts as a USB Audio transport and connects to a USB DAC – as long as audio data is sent over network from other PC / NAS / media server or from Streaming services.

Best upgrade for JPLAY dual PC mode


For JPLAY users looking to elevate performance of their dual PC setups, installing JCAT NET Card FEMTO in both Control PC & Audio PC is most likely the biggest sound quality improvement currently possible. Connect both PCs (JCAT NET Cards FEMTO) directly with a high quality LAN cable such as our JCAT LAN or JCAT Reference LAN Cables and enjoy vast sound quality improvement.

JCAT NET Card FEMTO not only improves sound quality, but also provides increased stability particularly desired with most extreme 700Hz/0.01s DAC Link/PC Buffer setting in JPLAY.

External PSU option

Even though there are ultra-low linear power supplies exclusively on the JCAT NET Card FEMTO, for best performance it is recommended to connect external linear 5V PSU (such as our 200W or 400W linear PSUs) as the source of power instead of using computer PSU.


• Audiophile PCI Express GbE LAN adapter
• Ultra-low noise linear regulators and filters eliminate noise interferences from PC
• No switching power supplies anywhere
• FEMTO Clock Technology (Crystek CCHD-957) lowers jitter below measurable levels
• Industrial grade components with operating temperature range from -40* to +85*C
• Enterprise level Intel i350 Ethernet controller
• Gold plated high durability EMI shielded RJ-45 connectors
• Two LAN ports supporting up to 1Gbit connection speeds
• LED-off feature to counteract noise
• Requirements for optional PSU: 5V/1.5A min
• PSU can be supplied from computer PSU via LP4 connector or from an external PSU via 2.1/5.5mm center positive DC jack connector
• Low-profile & full-height laser cut PCIe brackets included
• All x1-x16 lane PCI Express 2.0 slots supported
• Supported operating systems: Windows (all editions) and Linux

The JCAT NET Card FEMTO is available now for 422EUR at JCAT online shop. ►

For customers who would like to purchase x2 NET Cards FEMTO (for Dual PC mode), the price is 800EUR (instead of 844EUR). Ask for the discount via email!


by admin
September 15, 2016

USB playback redefined

3 years after the release of the first revision of the JCAT USB Card, designed to enhance USB Audio playback experience with desktop PCs, we proudly present its successor – the JCAT USB Card FEMTO.

Even though the performance of the original JCAT USB Card was excellent and by many customers and professional reviewers considered best on the market, our endless pursuit of quality led us to new developments that set the bar at the level we have never thought would be possible with computer based USB Audio playback.

FEMTO Clock Technology

We have found that the quality of clock used for generating USB Audio signal at PC side is as important for sound as the quality of clock in DAC. Therefore for the new revision of the JCAT USB Card we incorporated one of the finest clock oscillators available, Crystek CCHD-957 which has been designed specifically for High Definition Audio. It features a typical low close-in phase noise of -100 dBc/Hz @ 10 Hz offset, and a noise floor of -169 dBc/Hz. With this extreme low phase noise performance, you will “Hear the Difference”. The Crystek Femto Clock which is located just a few millimeters away from the USB controller chip is powered by a dedicated ultra-low noise linear regulator for maximum performance.

Ultra low-noise regulation

In the previous revision of the JCAT USB Card, the USB controller’s digital core 1V power was supplied from the PC via PCI Express lane. We redesigned the card so that all internal circuits are powered by ultra-low noise linear regulators exclusively if any 5V power supply is connected (either external or internal).

Although the JCAT USB Card FEMTO will operate without 5V for self-powered USB devices, the best performance can be achieved with an external high quality 5V power supply. You can use the newly released 100W linear power supply from our JCAT shop or other high quality linear or battery 5V PSU.
If high quality 5V PSU is not available please connect internal computer power supply to the LP4 connector on the card and switch jumpers J5 & J7 from default position 1-2 to position 2-3. By default the jumpers on the card are configured to use external PSU via DC jack connector on the PCI-e bracket next to the two USB ports on the card. If PSU is not connected then it is impossible to filter well.

JCAT USB Card FEMTO can benefit additionally from full galvanic isolation provided by our JCAT USB Isolator. We recommend using JCAT USB Cables for best sound quality.

– audiophile USB Audio output for USB DACs & USB-to-S/PDIF converters
– ultra low noise design for high definition audio playback
– ultra low noise linear regulators and high quality filters designed to eliminate noise interferences from PC
– Femto Clock Technology (Crystek CCHD-957) lowers jitter below measurable levels
– uDP720201 NEC controller
– high durability gold plated USB 3.0 connectors from Amphenol
– two USB 3.0 connectors supporting Low Speed (1.5 Mbps), Full-Speed (12 Mbps), Hi-Speed (480 Mbps) and Super-Speed (5 Gbps) data rates
– 5V PSU can be supplied from computer PSU via LP4 connector or from an external PSU via 2.1/5mm center positive DC jack connector (the 100W linear power supply recommended for best SQ)
– both full-size and low-profile PCI-e brackets included

The JCAT USB Card FEMTO is available now in our JCAT online shop ►

Only in September JPLAY owners can purchase the card with a 50EUR discount! The discount does not expire for customers who purchased the previous revision of the JCAT USB Card.
Please contact us if you are a customer and haven’t received the coupon code.

JCAT USB Isolator

by admin
August 3, 2016

Clean up your USB Audio signal

The JCAT USB Isolator blocks all noise coming from a PC and re-generates clean USB signal from scratch. It is capable of transmitting USB Hi-Speed (480 MBit/s) while providing full galvanic isolation up to 2.5 kV of both data and power lines – ideal solution for any sensitive applications requiring high-speed data transfer such as high end computer audio.
Recreating and reclocking of USB signal is done by a fast FPGA-based circuit inside the JCAT USB Isolator’s aluminum housing. The enclosure acts as a shield against harmful electromagnetic interference (EMI/RFI) to further minimize noise. Breaking all the noise coming from a PC results in vast sound quality improvements.
JCAT USB Isolator is a perfect solution for computer audiophiles seeking maximum sound quality from their USB DACs and USB-DDCs regardless of whether used with a PC, laptop or Mac.
JCAT USB Isolator can work alone or in chain with our JCAT USB Card. We recommend JCAT USB Cables for best performance.



- Featuring world’s first industrial High Speed USB Isolation technology from Intona
- Provides galvanic isolation up to 2.5 kV to the USB bus in all speed modes: Low Speed, Full Speed and USB 2.0 High Speed (480 MBit/s)
- Plug & Play transparent operation, no drivers needed
- Supports all USB-Audio formats and sample rates
- No separate power supply needed; ultra low-noise linear regulation onboard
- Reinforced USB Connectors: Type-B on PC-side, Type-A on device-side
- Housing made of brushed aluminum
- Dimensions: 13 x 6.5 x 2.5cm. Weight: 170g

The JCAT USB Isolator is now available and can be purchased in our shop here: ►


by admin
May 4, 2016

JPLAY will be used in combination with the MUTEC MC-3+ Smart Clock USB at the High End 2016 in Munich (Hall 1, Booth A08). See you in Munich!