So the S2 DAC defaults to USB power - but if a valid 5V is detected on the mini USB “power” connector, the DAC automatically uses the 5V source (then the USB input is only used for signaling).
The confusion in the manual is that is better to use the DAC “self powered” via USB then use with the supplied POS switching PSU that should only be used to power the DAC when the SPDIF inputs are used without power from the PC USB connection.
If you have a Decent linear PSU then its your best option - there is a significant jump in SQ when using a decent linear supply. The MiniStreamer can provide a clean supply to the S2 DAC.
All S2 are being built to my original spec - a few early internal engineering units built by the sub contractor used sub par Caps. before they received the correct Lelon organic Caps - these units where not shipped to customers but used for Photoshoots and internal testing etc.
Good luck seeing any units state side - from what I understand ProJect cannot meet demand here in Europe - so I guess forget thinking about supplying to the US at the moment… Maybe a few units will make there way over but you can understand there local markets are easier to serve in such situations.