Did not hear a difference Vince; I went with the 7700 because I plan to keep this Amp a very long time and I want to have the power to run any speaker I might ever desire and this amp will do that.

When I installed my 7700 I did have a ground loop problem that I did not have with the 7125 and this was because the 7700 has a 3-prong plug where as the 7125 does not. I found the cause of the ground-loop hum in a couple of minutes - it was a dimmer switch for my ceiling fan. I have been wanting to put in a remote controlled fan so this was the perfect time to do it; the remote controled fan (Hunter) also dims the lights with the remote so no dimmer switch is needed.