250TH single-ended amplifier drived by step down inter stage transformer
I built this amplifier for homage to Mr. Shishido. He has been respected for many tube amp builders. He used transmitting tubes for audio amplifiers. His method is to adopt interstage transformer to drive final stage tube (old type glass transmitting tube, RCA 800, 805, 808 etc.). His innovation is to reduce magnetizing of drivetransformer by reverse current direction of the primary coil and the secondary coil. This method is useful fo