Hey guys, I need some help with figuring out this old fender bassman head I have. I've owned it since 2009, and have mainly used it for recording bass (guitar also), since it isn't loud enough to keep up with most amps in a live setting. I need some help identifying it correctly since I'm finally going to get rid of it, since it's been collecting dust as of late. Can anyone help me out? I know the circuit is more desirable out of the two (its an AA165) but I don't know what the production number means, or the "OH" stamped randomly in the corner. Thanks!