I currently own a H/K AVR-525 reciever driving Ascend Acoustics CMT-340 l/r mains, CMT-340c center, and CBM-170 surrounds. And I have been extremely happy with the combo, but ofcourse, upgradeitis always looms. I have taken the speakers a couple of times to other places for listening sessions. Both times seperates were used, the latest being a Rotel 1065/1075 combo. And before that, I believe the amps were Aragons, do not remember the pre-amp. At these sessions I noticed that the lower mids/upper bass seemed a little tighter. Am I correct in assuming that it probably has more to do with the power being delivered to the speakers? Or is it more so the preamp? If it is the power amp, I will probably start on my road to seperates there. If not, I will hold off and save for both a pre-pro/power amp. Suggestions on an amp to mate to the 525 are also appreciated.