I have a Kenwood VR-507 amplifier. It has developed a problem where the amplifier will make an audible clicking sound and then the center channel and the subwoofer outputs stop working. Hours or days later, I'll here the same clicking sound and those channels start working again. I downloaded the service manual for this amp and it has a single relay that specifically protects both center and sub. I'm imagining that the problem is somehow related to this. I have minimal knowledge of audio electronics, but I know how to use a soldering iron. Is a relay a generic part that can be replaced, or is it a manufactured part specific to its amp? Or is it more likely that the relay is fine but something else is wrong with the amp that is causing the circuit to kick in to protect the speakers?