That's exactly what I'm looking for, Rich-n-Texas.

I did some testing just now and found out that the "control out" jacks are the same as "trigger" jacks. When the unit is turned on, it sends a 12v signal.

Now the question is, is the amp capable of receiving a "trigger" signal?

With a little more testing I answered that question. The answer is no. The amp only has a "remote in" and "RI" jack, which is meant to be used with other Onkyo components.

Looks like I'll be getting my lazy ass off the couch.... UNLESS I can figure out a way to wire some kind of 12v relay and use that to switch the amp on and off. That actually sounds like it would work! Now I just need some schematics of the M-501 to figure out where to tie in the relay. Actually, I can just tie it in to the current switch!

I'm excited now! Does anyone think this is feasible?