Andy Mazur’s switched-on Champ

As-standard, the Champ’s circuit is low gain. It growls with overdrive only when the amplifier’s Volume pot is wound up. Andy wanted more gain options for his WF-55, and the result is this. There are switches for adding cathode bypass capacitors to the preamp valves for more gain, a Princeton-style Tone control, a feedback-defeat switch and also a 3-way power switch.