JTM clone with dc voltage leaking into the signal path.

[catstrat]

I have a JTM 45 clone on my bench that has dc voltage on the Pots. I've removed all the tubes and coupling caps and it's still there. Any ideas. Am i overlooking something?

[loudthud]

Leakage of the component board is a strong possibility. What is it made of? Do you see voltage on turrets or eyelets with all components and/or wires removed? Moisture or acidic soldering flux can cause this. Sometimes cleaning or drying the board with hair dryer can reduce the leakage, but it may come back. The best option is to replace the component board with one made from G10 PCB material.

[catstrat]

JTM 45

Thanks Loud Thud. The board looks like a wax coated cardboard like Fender use to use. Your suggestion is worth looking into. It's been so humid here in last few weeks. I'll go over it with a hair dryer and see if that helps. The other thing ,i was getting dc on my guitar pots also. They were scratchy just like the amps pots. This amp is a "Tube Guy" amp made in Lousiana somewhere. I emailed him about it and he said he had some bad pots early on and he had to change them all. So let try the Hair dryer and i'll let you know. Thanks.

[big_teee]

I tried to use a homebrew board made from some local fiberglass, on my last build.
I had that same issue, Just like LT said, and ended up scrapping it and making another from the light green G10 from TubeDepot.
https://tubedepot.com/t/diy-central/...d-making-parts
From now on I will just bite the bullet, and buy the good board to start with.
T

[Mick Bailey]

I made a beauty of a 5E3 with some lovely brown phenolic board I had (new). I wanted to cry when it leaked DC. Total scrap. I also now only use the green stuff. I want an amp with a 60-year old sound, not one with the problems of a 60-year old amp.

Just recently I had a Two-Rock 'Dumble' with the kitchen-worktop woodgrain Formica boards. Now that would be a lottery these days - who knows where it comes from and whether it would be leaky.