Interesting Ampeg Reverberocket R 12RA I believe 1963 based on the speaker datecode. She had 7591 output tubes which the circuit diagram on the back panel called for but the wiring was set up for 6V6.. confusing.. one reason she was not working.. Turns out she needed all power supply caps replacing and the power transformer… output tubes.. and the output transformer gave up the ghost during testing.. One of the preamp tubes was also on the way out and crackling all good now. Great sounding reverb and tremolo (bias style trem) Was a pain to work on as the chassis is very cramped. But now a great sounding under-appreciated amplifier, I could not stop playing her!