WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
does anyone know if there's any source/supply of 12sh7 tubes other than cannibalizing old units or maybe a swap or easy mod to something more common for this device as used in a Heathkit T3 Visual Aural signal tracer.