Well, I found the transformer, and it does have a 12v setting. Woohoo! The end of the cord had already been stripped as well, so I have the two bare wires that I need for the RPA-1.
I think that I'll wait until tomorrow to give it a try. First, I need to cut a hole in the back panel of my entertainment center to have any chance to plug it into my receiver. Second, the fingers on my left hand have this persistant ache at the moment. Why? Well, the Belkin's power outlets are on the back panel...so, I use touch to figure out where I need to plug things in. Well, I was transferring a plug and didn't quite get one of my fingers off of one of the metal prongs before it entered the socket. Zzzztttt. A "nice" little jolt. Not the first time, but still not one of my favorite experiences. So, I'm going to take a break tonight and just enjoy a final beer.