- Dec 3, 2005
I would think he would put resistance in series with the tubes being used. Measure the voltage drop required after the amp is up and running, calculate the resistance needed, divide that in half and put a resistor inline on either side of the heater string to keep the voltage split evenly across the tubes. Then either a pair 100 ohm resistor or pot to go to ground, or use an elevated voltage.
The PT has a center tap for the heaters, so OP can pick whether they want a humdinger/elevated heaters or not. I have yet to need it on any amp...