Anyone ever hear of a Sunn PA Twelve? I picked one up in well used state, but functioning and can't find jack on it. Anyone know? The guy thought it was tubes, but with it instant on, it can't be. 200w/channel at least. I will play around with it, might be fun. Got it to have something I can easier bench test stuff I am working on or repairing. Need some schematics and possibly sources for parts. Thanks!