I have got the second new Usbridge (the first was one has had a broken ssd port) with Volumio on emmc. I tried run my Mytek Brooklyn DAC+ first time and I couldn't select the USB output, after some minutes it appeared. After that I made a reset, because the Spotify plugin didn't worked. Now the USB output is fully gone. No USB/no DAC selectable. The DAC is working without problem with my Mac an another RpI via USB.