Early 1960s McIntosh MC275. Speaker Wiring??


Stumbled across a 1960s McIntosh MC275 Amp in pristine condition at a yard sale. Issue is, the screen printing on the unit is all but rubbed off. Can’t decipher what is what in terms of outputs/inputs. Does anyone know where I can view a diagram? I think I’ve got the inputs figured but as far as the speaker outs, I know there are pos/neg terminals that serve different Ohms but I can't tell what is what. Want to hook up speakers but want to make sure I’ve got it right. It’s basically this unit below. (I scraped this one off the internet. Mine is the same but without the screen printed detail on the ins/outs)

Thank you for your help!


This should help with connections,


How long has it been sitting without being used? If it's been a few years, it would be best to bring it up slowly with a variac, and never turn it on without speakers connected.

Thank you! Exactly what I needed! It had been used frequently but the person who removed the ins/outs didn't take note of where things were.