Are you able to use an external or outboard DAC with this AVR? I have an OPPO-103 and I use both cd's, SACD's and mp3's. I'm in the process of a full upgrade. Just purchased Vandersteen Signature 2ce's and a Klipsh RW-12D subwoofer. The plan is to go to seperate components (amp and pre-amp) down the road. In the mean time, I'd like maximize the sound quality with what I have. Any ideas?