Presence control problems

[Phil_S]

In my recent build, I can't quite get the presence control to operate as I'd expect it to. There are two symptoms and I am unsure if they are actually just one problem or two.

I hear two things. First, I generally can't move the Presence pot lower than 12 o'clock (between off and half-way). It needs to be more "on" than the 12 o'clock position to prevent squeal.

The other problem is vibration-related. I hear a buzz that goes away if the presence pot is turned up pretty far. I've got the 100K feedback resistor on the outer leg of the pot. I'm wondering if I should move it to the output jack. Should I expect this to make a difference? I'm just trying to assess if it's worth the effort, as my soldering technique on jacks is not always what I'd like it to be.

Thanks for any suggestions that miight be out there.

[tkdrew]

I had the same problem with having to have the knob up more than half way on a plexi build, try swapping the plate leads on the output tubes. I wouldn't be surprised if the other problem goes away too when you fix the presence issue.