I have a JVC sh77 which has 3 sets of pre-amp outputs (front, back and subwoofer amps). Thing is, I am only using 1 amp. I have 8 speakers being powered by an Orion 25x2 amp. Is it possible, somehow, to get the front to rear fade to work? On my old reciever, it had just one set of pre-amp outputs and I had it wired exactly the same and the front to back fade worked just fine.