Sorry for your loss but glad you got the system up and running and obviously that was an emotional event.
It just sounds like your father missed a note stating to connect both amps up and as you discovered with an extra cable once that was complete the control unit was happy and music ensued.
So no do not disconnect the other mc501, you need both. I think the controller was intelligent enough to know you were missing one output connection and halted play until it was made.
An excellent system btw that you should enjoy immensely.
It just sounds like your father missed a note stating to connect both amps up and as you discovered with an extra cable once that was complete the control unit was happy and music ensued.
So no do not disconnect the other mc501, you need both. I think the controller was intelligent enough to know you were missing one output connection and halted play until it was made.
An excellent system btw that you should enjoy immensely.

