“I bought a Double Six power transformer and a Double Six output transformer, and I used the Double Six schematic as a starting point. I removed the complete tone stack, added a GZ34 tube, a 5V transformer for that GZ34 tube, added a switch to choose between a diode rectifier and the tube rectifier, added a 6.3v pilot light, added a 3 position bright switch, a second input (high and low).
“Also changed the 3 position rotary switch to a 4 position, so there is also a standby mode on it. The last modification is at the back of the chassis. There is an extra potentiometer that is a negative feedback control pot. Off course I needed to change some components and change some of their values to get things working as they should.”