Switching between network and USB for output

[peter.rayner]

I've a synology NAS connected via ethernet to a PS Audio Directstream, working beautifully. I also have a PS Audio Sprout I would like to use as a headphone amp. It takes optical, USB or bluetooth as inputs. I can stream to it from my linux laptop using mplayer. I'd like to be able to stream direct from the NAS. Hence two questions:
1) Can minimstreamer stream over USB at all? I don't see an option for choosing output.
If not then can minimserver use another streamer?
thanks in advance