This is very interesting, I didn't know we had such a category of device available! It's like an un-opinionated transport player.
I just plugged in the optical out of my RME Babyface Pro, I'm not sure how this exactly works, would this essentially make my computer a transport with that audio interface's optical out? The other question I have regarding optical are about the sample rates, using tidal atm but not sure what it's going to do with tracks that are at above 96kHz,, manually switching the mojo goes to red and is silent, as it's 96k.
If a source is 44k and my interface is set to 96k, is there an upsampling going on somewhere, if so where? In audirvana we can control this and adjust some parameters to our liking, but on a system level mismatch I'm not sure where this is happening. It's all a bit murky to me at this point. I need to read up.
edit: I did an A/B test with the optical and not with DSD native and regular CD quality, I found the USB in to be more exciting, my optical cable is ancient and I think the RME ( can do 200khz, though mojo2 cuts out above 96k ) is messing with the data stream. The USB sounds like a different beast with my options.
Since I use my RME for audio production work sometimes, I have eliminated a lot of the ground loop issues etc in the past, so my system is generally quiet, sometimes android studio's emulators go nuts but that's an isolated case. And yes, I had a case of white noise where my m1 mac had a notification about a USB device taking too much power and has been shut down, this has happened before with other devices but it tends to happen once or twice before the device doesn't cause it again. Sounds like a macos thing for flagging and confirming passively this is indeed a user requirement and to just deal with it.