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My bench went from a 40% success rate on old tube amps to over 80% after I started checking the bias voltage first thing.
For about a year, I was really struggling with restoring vintage guitar amps. I'd dive straight into recapping and replacing tubes, but a lot of units would still have issues or fail again quickly. My partner said, 'You're missing the forest for the trees.' So three months ago, I made a new rule: the first thing I do now is hook up my multimeter and check the bias voltage before I even clean the pots. It turns out a huge number of the problems, like weird distortion or low output, were just from the bias being way off from someone's previous tinkering. Fixing that first has saved me so much backtracking. Has anyone else found one specific initial check that solved a ton of recurring problems?
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alex_wilson7914d ago
Yeah, @jamie_carter87 is right, checking the screen grid resistors next is a smart follow-up.
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jamie77013d agoMost Upvoted
Agree with both points. Screen grid resistors can drift high and cause all sorts of weirdness. But you gotta know the bias is solid first, otherwise you're chasing ghosts. Always start with the simple, known voltage check. It's the fastest way to rule out the big stuff. Then move on to the resistors.
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