Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Effects => Topic started by: luthierwnc on November 13, 2023, 04:11:20 pm
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Hi all and hope you're well. I stripped and re-redid the circuitry on the unit which got rid of a pesky ground loop. There are two thorns remaining in my toe:
1) it has an annoying crackle/pop intermittently. I suspect the seven pin socket since it is the only thing that hasn't been replaced. If something else comes to mind I'd like to know and 2) The cap on the second 12AX7 gain stage and anywhere on the shielded wire to the output jack is incredibly sensitive. The slightest movement makes noise. Tapping it with a chopstick is excruciating.
The schematic and an actual picture of the offending component (red arrow) are attached. The cap was wired in a slightly different place in the first rebuild and did the same thing. It strikes me that is a really raw circuit taking the full gain of a pentode. It puts out a lot of gain too. If anyone has ideas to tame it down, I'd be grateful.
Thanks for looking, Skip