I also picked up a 6505+ head a few months ago pretty cheap. Cheap enough that I would consider myself a dumbass if I didn’t get it. It had been 10 years since I had one and as soon as I plugged in I had a ear to ear grin. It’s just a killer amp. I haven’t even bothered to check the bias or clean the amp like I do with ever other amp I get. It works. It sounds killer. Done. Haha!