Volume pot - dead spot - weird

[Watto]

Hi Folks,
I have an AB763 deluxe reverb build with the trem/vib circuit removed and reverb on both channels, the normal channel has a 5E3 style mod to it and the Vibrato channel is stand (minus the trem circuit removal)

It's grounded using the Hoffman system , with a copper wire across the back of the pots etc, it's quiet as a mouse (hum wise)
All works well but there's a dead spot on the "Vibrato channel" pot . between 10 and 12 o'clock. It doesn't drop completely , it's a volume drop of approx 50%, after 12 it comes back with a punch .

I know it could be the pot , but I thought I'd ask the brains trust here first to see if they had any ideas. It's a pain to swap out the pot with the earth bar at the back , Any thoughts of what may cause this before I swap it out would be appreciated

regards
Watto

[eleventeen]

You probably have a pot replacement in your future, even if just to test out the theory. Before that, I would see if spray cleaner did any good. DeOxit is the best, but it's expensive. Dead spots are rare but possible. Maybe there is a piece of dirt in there that is causing the wiper to back away from the horseshoe of res material at that spot. If you get no relief using spray cleaner, I would buy the repl pot and wire it in with stiff, short pieces of wire, hanging in the air, and test out whether that's your problem before going through the ritual of cutting the original one out.

[Watto]

Thanks Eleventeen,

I've done the Deoxit, forgot to mention that, I like the idea of wiring it out of the chassis first , I'll give it a go, I went with CTS and I'm surprised it's doing this after only a couple of years

[Willabe]

I went with CTS and I'm surprised it's doing this after only a couple of years.

Since the pot worked fine for a couple of years it sounds like a bad pot alright.