To follow Elisabeth.
You have a few options if you MUST go this way.
First you must understand that desire not to use PC power is the desire not to carry ground noise to your DAC, so:
1 Use dedicated server where this problem (and, hopefully, many others) is solved
2 Use USB Cable with interface like iFi where you can use iFi power (it will work even better if no power will come from PC to your USB port). Its also not cheap as you need to buy iFi as well as two quality USB Cable (to and from iFI). iFi supplies terrible quality USB cable which, IMO, negate advantages of iFi
3 Use USB Cable where noise is "grounded" .
From my past experimentations with our Musica Pristina servers the last solution is the best.
All The Best
Simon
Musica Pristina
