Looks like a Class 5 that you'd like to replace. Just throwing another option out there, I just picked one of those up locally that a previous owner had a master volume installed on in the back panel. Kind of a one trick pony but I just put everything on 10 and adjust the master to taste. Nice creamy classic rock crunch from that amp, probably wouldn't be my only amp I guess though. Thing sure gets LOUD without that master volume.