I have one other question. I'm not saying that I could detect a difference but my understanding is that the optical connection on the Mojo2 supports up to 24 bit 192 kHz while the USB inputs support up to 32 bit 768 kHz. So with a high end system wouldn't it be better to use the USB inputs?
I was using the Duoo X10Tii with a moonaudio optical cable to the Mojo 2 for a while before switching back to the Poly.
The optical connection sounds wonderfully clean, but, at least compared to the micro-usb connection, seemed just, I dunno how to describe it...maybe "thin"? It wasn't thin though, just seems "thinner" than the usb connection.
Which, isn't necessarily a bad thing. That slightly thinner sound brings extra sharpness for large symphony orchestras, which is almost magical to listen to. But more popular songs don't quite have the oomph or musicality that the usb connection has. Again, I am talking about a tiny tiny sense of difference.
The "extra sharpness" of optical, by the way, is a phrase I'm leaning towards because I don't want to say "greater separation, greater detail, better resonance, faster attack and decay, cleaner transients" because none of that is true. But there is a sense of that little extra bit of sharpness that makes symphony orchestras really shine.
The difference is tiny enough that it very well could be my imagination. I consistently have this impression when switching back and forth, so I "think" it's a real perception. Then again, it's not a blind test, so there's no way to be sure that it's not just my imagination.