Dave - You'll probably have this question answered before Audiogon prints this response, but just in case, here goes.
Receivers of that era often had provision for multiple speaker connections with some means of selecting the speakers you want to power - or no speakers at all. Look for a "speakers off" position, select it, and use your phones.
Receivers of that era often had provision for multiple speaker connections with some means of selecting the speakers you want to power - or no speakers at all. Look for a "speakers off" position, select it, and use your phones.