Model 41-287 volume issue - Printable Version

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+--- Thread: Model 41-287 volume issue (/showthread.php?tid=26123)

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RE: Model 41-287 volume issue - RodB - 12-15-2025

Excellent! Another thing to check is the negative voltage on the grids of the audio output tubes. It should now be -18 to -25 volts. Do you have Deoxit F5 for the pot? Don't put a lot of faith in the tube tester. I experience it all the time, a tube tests OK then you put it back in the set and later you're replacing it. It's good for eliminating dead tubes, the rest it's 50/50. Sounds like you're on track.

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RE: Model 41-287 volume issue - mikeyg - 12-15-2025

I will definitely check those grid voltages. If they aren’t what they need to be what might be the next step to check? I have some contact cleaner. It’s not deoxit but I have used it before. I’m going to check my solder joints real good at my pot as well. That actually ended up being my issue. I had a cold solder joint that just wasn’t making good contact on my ground. I have a couple of extra 41 tubes just want to see if they are any better than the ones that are currently in there

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RE: Model 41-287 volume issue - RodB - 12-15-2025

I hate to say it but resistor 61 produces the voltage. That section reading high would be the cause. I'm not so concerned about it being high because it probably produces a greater bias than needed. If it was lower then it would cause the bias to be more positive than it should be and the tubes will conduct a higher than optimal current.

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