Interesting conversion here. This is a vintage mono hi-fi tube amp with 12V filament tubes - 12V6, 12V6, 12SL7, 12SN7, and 12SQ7. There is a 5Y3 rectifier. This has been modified into a guitar amp head. Power caps have all been changed, 3-prong plug added, jacks have been changed to 1/4" and moved to the front of chassis.