What an odd little amp. Single ended amp using a 6BM8 output tube. 12AX7 preamp, the 6BM8 contains a triode to make the oscillator for the trem, and a 5Y3 rectifier. Works and sounds killer, I installed a 3 pin AC cable. Lots of cigarette burns on top, original Jensen 8" alnico, just a cool little amp.
The reverb echo pertains to the reverb pan, no longer present. What made this amp so odd is in order to have reverb, you had to drive it with another guitar amp- literally the output of another amp plugged into the reverb input on the front of this amp, through a big resistor, and drove the pan. Wiring and such is still inside, may work with a pan, but on this model the reverb would not work without another amp to drive it. But as a stand alone amp with tremolo, sounds great. Volume control, and tremolo speed. Get ready to rock. Thanks for looking!