Well, I haven't been able to get my just received unit to work. It arrived set for 220, but I changed that. It turns on, but the right side display reads 44 for every input, connected or not. No sound comes out from any input (I've tried both coax and the AES/EBU from 2 different sources so far). When I called NuForce, I was unable to speak to anyone who could help (model too new??).
While I am not tech support, I have a few hours experience with the DAC and had the same problem, because silly me, I didn't check the voltage, since I thought it would be preset. So if anyone is not getting sound the very first thing is check the voltage which will likely be set for 220v.
Second; the Coax digital inputs are listed on the rear as COAX #1 AND COAX #2, but they are actually DAC inputs #3 and #4. Those would be the first two things I might tell you to check.
Not sure about the AES/EBU, but make sure it is set to the correct DAC input according to the manual.
I have over 100 hours on the one we are using at The Home Entertainment Show (ROOM 411) in Newport Beach this week end and it is spectacular. Full, clear, and excellent bass.
In fact, when I left we had it set up as a Preamp and DAC and the bass was so good that we didn't even turn on the sub. (and may not in that small room)
Hope that helps