My office setup is my Dell Studio PC with a digital audio output connected to my old Onkyo TX-NR600 AV Receiver, recently liberated from my Home Theatre system. Connected to the Onkyo are 2 new Monitor Audio Bronze BX2's and a new Polk Audio PSW-110 sub. My only music souces are CD's and various international classical music channels on vTuner, such as RCO and BBC3, that I run through iTunes. I do this for 2 reasons:
1) I can set all of these up in Internet Songs, so I have in effect a folder of favorites that are very easy to access.
2) There is a nice graphic equalizer in iTunes that I have used to even out room acoustic problems in my office. (aside: Why doesn't there exist a good graphic equalizer for Windows 7? If I use Paradox or Spotify, I don't have access to any equalizer.)
The vTuner channels mostly have high bit rates, and the sound quality of my system is already very good, but I think it could be better with those very capble BX2's.
So I an thinking about replacing the Onkyo with a quality stereo integrated amp like the Yamaha S500 (the Marantz 6004 is too expensive for my budget). But I realize that my system is currently using the DAC's in my Onkyo, since I sending digital output from the PC. So I would have to either add a DAC as well as the Yamaha or just leave the Onkyo in place ahead of the Yamaha just to make use of its DAC's. Will that work?
If I do buy a separate DAC, I believe I would prefer one with a digital audio input, rather than USB. The v-DAC Mark II looks good, but my God, it costs as much as the Yamaha.
So my questions are:
1) Will I probably get a lot of improvement by replacing the Onkyo with the Yamaha, with the rest of my setup the way it is now?
2) Will an exernal DAC show significant improvement over using the Onkyo for DAC purposes? Suggestions for a DAC?
3) Any other suggestions?