• 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.

Bias Adjustment point

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Hi all: Have a 100b yaquin KT88 Intergrated Amp. Decided to check bias after a year of use. Purchased a biasing tool for this. The first KT88 would not get a reading. The amp has a adjustment point for each tube accesible right from the top of the chassie.

Any turning of the adjust point would not provide any reading on the multimeter. I then fryed that tube! I have now a quad of new tubes and the first one still does not read bias nor allow adjustment. The other three tube bias and adjust fine.

Any idea what the problem is? How to fix it? Whats the risk of leaving like this. Sound is fine. Appreciate any help.

LarryRup
 
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