I say return it and look for a good used amp on Audiogon. If you are only using it for the 80s it shouldn't be too hard to find a reasonably priced 2 channel amp that will do the job.

2xM80 VP180 2xQS8 2xM3 HSU STF3 LG 60PS11 Denon 3808 ATI 1506 LCR 2xATI 1502 Oppo BDP-83