I've been trying a few digital sources lately. A very good combination seems to be using a Onkyo C-7030 as a transport and one of these as a DAC, connection is coax.http://www.ebay.com/itm/251473429943?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Detailed, great sound stage, tight timing, good dynamics, no warts. I tried optical / TOSlink. It had warts (jitter?).
I expect to give it a try using a PC, USB connected via an optional port on the DAC. This will provide a source for higher sampling than just 16bit/44.1k.
After listening to other players and combinations, this is very hard to beat. And at $400 for the combo, a very good deal.