Which part?

Let me see if I can clarify.

My EP350 is plugged into a wall outlet, as normal. I have a 12V ac/dc power adapter from Radio Shack plugged into my switched outlet on the receiver. That 12V adapter has a 1/8" (I think?) tip which plugs into the trigger port on the EP350. The power switch on the 350 is off. When the receiver turns on, current goes to the trigger port, which flips a relay (internal to the sub) which turns on the sub. At that point, the auto on/off (based on input level) takes over.

I am the Doctor, and THIS... is my SPOON!