@matrix @Duine you might still get noise since you're connecting to USB electrically, you're not isolating anything, and have to just trust that your USB DAC has proper isolation and stuff, that's probably why hifi equipment tend to have "ground lift" switch to actually isolate ground wire (i.e. for USB it's the metal box of the plug IIRC). If you really need electrical insulation period - use optical instead, but for me at least my Roland Rubix24 works great over USB, but it is somewhat hi-fi.