• 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.

thermistor for D3As to stop heater glow/flash

The D3As are AC heated. I am thinking of a resistor on a delay relay but have gotten distracted by another project. As far as rectifier it is a 5AR4 - but I use the Neurochrome Maida regulator. I highly recommend the Maida! Zero hum and very open sound. Thanks!