Whats the next upgrade for me?

I have learned a heckuvalot from the forum since I found this site. Mostly I've learned that my equipment is sub par for my expectations. I'm ready to upgrade my next component and am unclear as to what would benefit me the most. Please take a look at my current, humble gear and suggest what you think would be the best bang for the buck upgrade.

Eosone Bipole rears
AudioSource center
Yamaha 10" Sub
Denon DVD 1910 (DVI version, playing my CD's through this)
Denon AVR 2802
Carver TFM 15, driving the DQ-28s
Acoustic Research interconnects for everything

After we buy a new, larger house, I'm planning on using the DQ's and Carver in a new, listening room. The rest of the equipment will stay in the living room for a HT setup. I'll of course replace the fronts. Anyway, I have a feeling that most of the responses will be to get a decent source (CD is my medium). I'm sort of leaning in that direction as well. Or perhaps a Dalhquist center. I have a budget of approximately $650 for this next piece. Thanks for your thoughts.
new source, the most important component. everything down stream will be impacted by it.
Try clean power, ac conditioner, ultimate outlet, etc. you will be amazed, best bang for a buck. Earmeal
try to find and buy a master tape. it will make more of a difference than any component money can buy.

ok, it's not easy to find a master tape, but imagine if you had one.

the best source with the worst equipment sounds better than the worst source with the best equipment.