Wisnon,
I wonder if this Uptone Audio Regen device may improve the sound if usb cable is only one strand transmitting only data but not the 5v supply.
I am using a custom version of jcat reference and when connected to big 7 I switch off the ps of the usb audio output from the aurender side.
What's your opinion?
Marslo, in a word…YES.
Clean power is just a side goal of the Regen, not the main one.
It doesnt improve the sound of the cable per se.
JS did his experimentation and found out that USB packet noise is not a continuing stream, but rather a relay. Packet noise causes low signal integrity and that causes the PHY (physical layer of the USB receiver apparatus) to work harder and create ITS OWN noise downstream, eg in the Dac itself. So the noise you experience in the dac didnt come from upstream, rather the upstream noise dies, BUT, it induces the Dac's USB receiver to create new commensurate noise. These noises have at least 2 sources, in the PHY and the MAC. Regen does nothing to the MAC and that noise continues unabated. Not much can be done for that at present by any developed system. However, the PHY noise can be and is addressed by the Regen. In optimizing the Power Distribution Network (PDN) in the Regen (which is basically a specialized/high quality USB hub), carefully matching impedance (with the multi layer PCB plus carefully inserted resistors) and finally running separate power (this is about having a different grounding pathway from the Dac), the Regen causes a significant decrease in induced packet noise generation in the Dac. You block the handovver of the baton in the noise relay. He also somehow manages to lower the overall impedance in the Dac itself, which he asserts is a very good thing.
In summary, given his objectives and the fact that the Regen is placed as close as possible to the Dac's USB receiver (solid metal adapter is best), then the USB cable coming from the source to the Dac is less important and separate from the "magic" of the Regen itself. Of course, the better the upstream components, the less the Regen has to work and the better the overall result. The Regen has its own PHY, dont forget.
The working theory of why the Corning Optical USB cable was so good with the original GREEN Regen, was that it introduced more than 3 ohms of resistance to the Regen and that seems to improve the bass a lot. The new AMBER Regen incorporates similar resistance in the Regen PCB itself andf so is more cable agnostic than the Green.
Better explanations can be found at the Uptone site in the FAQs.