Peavey ValveKing 112 - BIAS mod - different mA reading

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MaoVi
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Joined: Wed Feb 01, 2023 2:03 am

Peavey ValveKing 112 - BIAS mod - different mA reading

Post by MaoVi » Wed Feb 01, 2023 2:24 am

Hello everyone

This is my first post on this forum, and I decided to create new topic because I couldn't find answer of my problem.

I modified Peavey ValveKing 112 and I added BIAS 50K pot with 15K resistor. I not understand how to add BIAS test jack, so I bought BIAS cathode probe adapter, and when I take measurements by decent multimeter I have huge difference between 1st and 2nd valve slot:
14.2mA and 20.1mA
I swapped tubes places, but readings are similar.

I will be grateful if someone could explain me what I doing wrong.
Currently I set BIAS to the same level like before this mod, but I wish to have them slightly warmer 31 mA.
Thanks

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