I'm using a Dspeaker Antimode Dual Core 2.0 as a preamp, dac, and room correction device. I run my 2.2 speaker system by using an XLR-RCA (DNM HFTN) cable for my 2 channel amp and the RCA Outs are run to my subs. The Dual Core has USB input for your MacBook and Optical input for your DVR. Remote volume and built in room correction also. There has been a lot of buzz around the Dual Core and some heavy hitter reviewers have given it very favorable reviews.
The Dual Core can also be run from a 12v linear or 12 battery power supply. I have mine on a 12v battery PS and have had a few friends comment that it sounds much better and more analog that way. The sound stage opens way up, music appears from a very dark background, and has more top end air.
Do a search and check out the reviews. :-)
Good luck,
http://www.dspeaker.com/http://www.simplifiaudio.com/