Hello, I recently was given a stereo system (Marantz) as a gesture of goodwill. I was pressured because of growing family to give my vintage stereo away some years ago. Dual turntable, advent pre-amp, Brysten amp, Dahlquist DQ-10's. The new stereo has a marantz stereo amplifier pm551. When I wired it all up the amp only plays one one channel. I put the speaker wires on A and A channel 1 and 2 they both play. My question to this group is should I have the amp fixed, or should I just seek out a new or used amp?