Bryan, I'm using it now as a preamp in my speaker system. Takes digital in from a Sony SACD (for 16/44) and a laptop, and analog in from my Sony HAP-Z1ES. Preamp out to Job 225 amp, and Gallo Strada 2/TR-1 speakers.
Overall, can't complain at all; I think it was JP# that said this was stupid good for the $, and I agree. Maybe it's a pre-read review biasing me, though, but I like the headphone out a bit more than the preamp outs. Resolution is great, but it sounds a bit lean in the mids and can get a bit brittle on top. NOTHING at all bad, I never feel the need to turn it off; but not as good as some of the better I've had/heard; and I don't get that sense from the headphone out. Apples to oranges, of course....
That review I allude to mentioned that headphone out is a class A design, and the pre outs have opamps in the path. Could be the reason, or again may just be pre-bias.
I have a 1/4" to L/R RCA adapter cable, I need to try that at some point to drive the amp, and compare to regular pre out. Just haven't bothered so far except for an early test using another power amp.