Well let me weigh in on this as well. Got the 7500 on Thursday and hooked it up today. Turned it on and....hummmmm. All 5 channels. Went to the manual and followed the instructions. First disconnected all cable TV inputs. Still humming. Then disconnected the unbalanced interconnects from the 990 pre/pro. No hum, quiet as a mouse. Started plugging in interconnects one at a time. Each time the hum was back. Maybe it's the interconnects? Pulled out my old Yamaha receiver and hooked up the same interconnects to the outputs that bipass the receiver's amp. Just a nice quiet hiss so I'm thinkin' it ain't the interconnects either. Maybe it's the 990 except there was nothing when it was hooked up to the 7125, in fact it was stone cold quiet regardless of how high I adjusted the volume. What's going on? I guess I'll be on the phone with Outlaw on Monday (if they're in on the holiday). Maybe I've got to try balanced interconnects.

The amp's performance however, is very nice. Made the new Axiom M80v2 speakers that I am trying out come alive. They seem to love the extra power and the dynamics have changed considerably. Very crisp and clear. Here's hoping I can get to the bottom of this because the amp sounds great.