although it wouldn't bypass the volume and tone control on the receiver,
connect the PAT5 to one of the Tape Monitor loop on the receiver, so you can switch the PAT5 in or out by just pushing a button, as long as you don't turn the PAT5 volume too high it should be fine.
If you can diy, modify one of the tape monitor in/out to pre-out/ power-in is the best way to go.
If you can diy, modify one of the tape monitor in/out to pre-out/ power-in is the best way to go.