Doubtless this is my own ignorance talking, but I don’t see anywhere on ropieee.org that indicates which USB DACs are compatible. I see RoPieee | Audio Hardware, which lists USB DACs that provide native DSD streaming, but nothing beyond that indicating which are compatible more generally. Is the USB DAC interface protocol so standardized that I can reasonably expect that any USB DAC will work?
More specifically to my needs, I’m looking at an amp with an integrated DAC with USB interface, like the SMSL AD18/SA300 or Loxjie A30. Would these work with RoPieee, or should I be looking for something more specific?
Does it mean that any audio device with USB connector will work?
No, some USB connectors on audio devices aren’t audio inputs but rather meant for connecting storage or for maintenance use (update firmware) only. Please check with the audio device manufacturer if you’re unsure.
Does it mean that I can use the full potential as advertised by the audio device manufacturer?
Not necessarily. Please read the data sheet and fine print also. Driver-less USB Audio Class 2 support tops out at stereo PCM 384 kHz and DSD256 (over PCM). Multi-channel support (if applicable at all) is limited to PCM 96 kHz or less depending on the amount of channels. Special support (a driver) is needed for higher sampling rates.
The listing of special driver support included in RoPieee. Manufacturers may also provide special drivers for specific OS’s on their homepage (today mostly limited to Microsoft Windows).