I just set the bias in my Super Sonic, using the test points on the PC board. Fender recommends 32 mV at each of the two test points when replacing the power tubes. I'm getting different readings on the two replacement tubes and settled by splitting the difference, one is at 30 mV and the other at 34 mV. As there is no way to adjust the tubes individually, is this correct and is it common to see a so-called "matched pair" of tubes be off by a few mV?
Fender also mentioned checking the power supply voltage at TP9, for a voltage of -54.5 volts. Why?
Thanks for any help.
Fender also mentioned checking the power supply voltage at TP9, for a voltage of -54.5 volts. Why?
Thanks for any help.