I was going to sell my 755 and replace it with 7700 for the hybrid setup which I'll describe below. I decided NOT to sell it. I replaced my CROWN DC300A's of varying vintage. I was biamping ES224s (electrostatics) with four stereo amps (8 channels).
When I listened after doing the swap and installing the 755 I was amazed to hear material on the recordings (these were live ones we did years ago on tape) that I never heard before. Unbelievable. And so I have 5 channels and am using only four. OK so there's extra (albeit shared) power and thus headroom. Wow. I am so glad I kept the 755.

Now to the 7700 in hybrid. The material we recorded years ago in discrete (in-line) 4 channel on 4 channel crown tape machines is meant to be played back as recorded (i.e. across the front of your listening room. So I have a hybrid system. I use five of the 7 channels for the usual 5.1 format. The SBR and SBL are fed from the 7.1 direct outs and their speakers are only used during the 4 ch playback (which I do a lot of). I feed the 7.1 inputs from four channels of a multi channel hard drive recorder.
So I have the best of both worlds. Anyone interested? Send email and I'll send schematic. And remember that AMPEX way back recorded music in 3 channels. I think RCA Living stereo was also done that way. So there is real prescedent here.
Besides that it sounds great.

I am very pleased with outlaw products.