Updates: USB cards, new LPSU

After getting additional feedback from two reviewers, the flagship streamer were tweaked and fine tuned which include a new 5V regulator board and all 6 rails on the main LPSU board populated.

The previous blog post on Nov 24 about product launch assumed Gelombang (A Festival of Sight and Sound) will happen in December 2021 and the plan was to launch the flagship streamer during the event in Kuala Lumpur. Gelombang was rescheduled to end-March 2022. The current Omicron situation makes it challenging to organize, participate, or attend any big events.

The flagship streamer will be ready for orders after a new website is created and goes live. This blog will be repurposed (no longer be about music streamer project) with selected contents moved to the new website.

Experience with Reviewers and their Feedback

One of my embarrassing experience making Windows 10-based music streamers work at reviewers systems is the need to allow streamer PC discoverability when connecting to a new network. It’s the way Windows work. It requires keyboard, mouse and monitor

Windows 10 new network connection needs confirmation to make PC discoverable
(Picture from How-To Geek)

If streamer PC discoverability is not allowed (the default if the prompt in the picture above is not responded with “Yes”), the tablet or phone apps (BubbleUPnP and Remote Desktop (RD) Client) will not be able to find and connect with the music streamer. It took me a bit of research and time to find the proper solution to make Windows automatically accept a new wired LAN network connection without compromising Windows security. This is a must-have feature since the streamer may connect to a different network switch or router, or maybe moved to another house. Since the connection is wired LAN in the house or showroom, not public WiFi, it only makes sense to automatically accept it.

Another question received from a reviewer (actually another person asked the reviewer this question) is on streamer’s ability to play CD directly since there is an option to put slim optical drive for ripping CD. This was tested. Windows Media Player (WMP) is one of the better options for playing CD since it comes with Windows 10. The fact that CD album artwork is automatically displayed is a nice WMP feature that VLC does not have. Controlling CD playback from RD Client needs edit of Group Policy setting for Removable Storage Access, otherwise the inserted audio CD cannot be seen from RD Client. Redirecting audio directly to remote PC can be easily done in RD Client setup before establishing connection.

While the CD playback audio quality with WMP is acceptable, the noise of spinning CD is annoying. Playing music directly from local SSD using JPLAY FEMTO remains the reference for sound quality (SQ). The slim optical drive should be used for ripping audio CDs, not for playback. WMP can be used for audio CD ripping.

New 5V Regulator Board

Since there is a spare unused 12V rail on the main LPSU board, it was used to generate super low-noise 5V dedicated for USB Audio with four levels of voltage regulation. In the pictures below, it is on the left side of the board, with LM1085 and LT1764A being the third and fourth-stage regulators respectively. Please note the use of Vishay MKP 1837 100nF Polypropylene Film Capacitors (3 black cubes) – these are expensive and hard-to-get, used as bypass capacitors with Kemet 22uF tantalum capacitors. The 3 secondary regulators (LM1086) on the right side are for SSDs rated at 1.5A each using Nichicon Gold output capacitors.

New 5V regulator board
Another view of the new 5V regulator board with cable to USB Filter

The main LPSU board is now fully populated. Originally, the spare 12V rail was meant to experiment motherboards with slightly more powerful CPU like Core i3 or i5 which need dedicated CPU 12V. Since the J5040-ITX is already sounding very good, the spare rail is now dedicated for USB Audio only.

Fully populated 6-rail LPSU board
Another view of the main LPSU board

USB Cards Evaluation

Two USB regen cards were purchased for evaluation:

  • Core Audio USB P24 OCXO

Some may be wondering which USB card is better. I used the USB cards to improve the sound quality of my own USB Filter. The new super low-noise 5V improves USB Audio output significantly. My preference now is not to use any USB cards, just use the USB Filter.

USB regen card is a necessity if the music streamer PC uses standard PC SMPS. The worst use-case is when motherboard’s USB port connects to USB DAC, and if this is compared to USB regen card supplied by an external low-noise LPSU, the SQ difference will be day and night.

Adding USB card is almost like adding flavor to food. Each USB card has its own sound, and it sounds very hi-fi instead of musical. Since I use Marantz SA-10 SACD player as one of the devices to voice the music streamer, I always compare the sound from SA-10 versus the sound of streamer’s USB Audio Output into SA-10.

SA-10 is a very musical SACD/CD player. The musicality is lifelike, especially with musical instruments’ decays. Instruments sound real. With a dedicated rail of low-noise 5V supply for USB Audio Output, just using motherboard’s USB2 header into own-developed USB filter gives similar or slightly better sound compared to SA-10 playing SACDs/CDs, but with the convenience of remotely controlling playback from a tablet.

When the low-noise 5V is used to power USB regen card, the sound becomes hi-fi. Decays are shorter, sound feels finer and bass becomes too controlled and unreal. Real musical instruments do not sound that way. Some people may prefer hi-fi sound instead of musicality. For me, I want to listen to music, not hi-fi.

Between the 2 USB regen cards I tested, JCAT USB XE wins as the better hifi-sounding USB card. The USB P24 is too polite with poor bass control. However, there are some problems with JCAT USB XE – it runs too hot with its heatsink temperature in the high 50s C, approaching 60 C. Due to Streacom FC10 case design, the PCIe card needs to be mounted horizontal with the heatsink facing down. Part of the heat which is supposed to get out from the heatsink goes back to the PCB. Once the temperature goes too high after continuous use, the SQ is no longer good. The USB P24 does not have this heat problem – it sounds better after continuous use. Maybe the JCAT USB XE should be tested when plugged directly into the motherboard when a different case is used.

A picture from previous post – JCAT USB XE heatsink facing down inside Streacom FC10

Updated Streamer Configurations

The updated LPSU design resulted in updated configurations for the streamers as given below.

Flagship Technical Specifications:

  • Windows 10 21H2 IoT Enterprise LTSC OEM
  • JPLAY FEMTO + BubbleUPnP on phone / tablet (phone / tablet not included)
  • All-in-one music streamer solution without the need for external power supplies
  • Best SQ with local music playback (stored in SSDs)
  • Optional slim optical drive for ripping CDs
  • Sounds good even without USB Audio regen/reclock card

Note: Linux option may be offered to customers who prefer convenience and not worry too much about sound quality. The use of Windows 10 resulted in very high SQ, but the users must be PC literate.

Entry-Level Technical Specifications:

  • User-installed O/S + playback (e.g. Daphile, Euphony)
  • For Linux-based O/S, music files can be stored into primary SSD
  • Final computer case design is still pending


  • Is it possible to buy LPSU only? Yes, in the future
  • What other motherboards have been tested with this LPSU? So far, only Pentium and Pentium Silver SoC mobos. We may offer LPSU with EPS 12V @10A for CPU in the future, with the other rails at 5A max.
  • Why the entry-level model is not ready? Due to the use of cheaper computer case and more compact LPSU board, the sizing of proper heatsink is challenging and is not done yet.
  • I already have JPLAY FEMTO license. Is it necessary to buy another license? Please contact JPLAY if you would like to transfer the existing license to another motherboard.
  • I only do music streaming from internet without local storage playback. The AA flagship music streamer maybe overkill for your needs.
  • I am not PC literate and not comfortable with Windows 10. What other options I have? Euphony is one of the better sounding Linux-based music player and is very easy to use but not cheap. You can also consider Daphile which is a free Linux-based music player.
  • What is Windows 10 21H2 IoT Enterprise LTSC OEM? This is not the regular Windows 10 which consumers can purchase. Only system integrators can buy and deploy the license of Windows 10 21H2 IoT Enterprise LTSC OEM. It does not come with bloatware like regular Windows and sounds better compared to Windows 10 Pro. OEM license means it is tied to the motherboard and is not transferable.

If you have any comments or questions, please post it here or send private message.

By Anwar

Dr. Anwar Ali is a consultant in the area of Operations Research / Decision Science. During his free time and as a side business, he builds high-performance and moderate-cost music streamer.