Volumio 2 works with i2s & USB DACs. There are some DACs that people have reported to cause problems for one reason or another … have a look at the compatibility list here.
Hmm, I see why I missed the option… it wasn’t there!
Is there some kind of logic that only displays it when it sees a USB DAC connected?
The audio output somehow un-configured itself and now I can’t see any option for USB.
All I get now is Audio Jack, HDMI out and Hifiberry DAC (probably because I had clicked i2s dac option previously and restarted).