• 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.

Tube voltage help

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On the Plates of the 12ax7 it's supposed to be 65 volts respectively.
But on mine it reads 63vdc pin 1 53vdc pin 6. Everything looks ok execpt the one of the 470k resistor read 460k, Other than that I can't find anything wrong. Any Help please. BTW all caps have been changed. and the Rectifier has been changed to diodes, With a bigger droping resistor R12 to get the voltage right.
 

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Hi 24kilo,
Have you tried a new 12AX7? You have to remember that a dual triode is a pair of tubes that are individuals. They are not matched. I will assume the caps were changed with new poly types.

What exactly is the problem you are having?

-Chris
 
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