Klone gain pot weirdness. Ideas?

[nate77]

I just threw together a Klone from aion electronics and I'm experiencing some weirdness from the gain pot. I've built a fair amount of these things an this is a new problem me. The gain pot ( which is a dual gang) works as it should until about 10 o'clock then It fizzles out and the volume drops.  I'll get some pics and such up but I was thinking that half of the pot maybe isn't working as it should since its a dual gang. Whatcha guys think?

[mth5044]

If you think it's the pot, clip the wires and measure the resistance as you turn it.

Also,  http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[nate77]

Ah, that makes so much sense I'm embarrassed it didn't occur to me. Thanks man

[aion]

I would be surprised if it was the pot itself. It's certainly possible but my money's on something else. What's happening is that the pot is shifting the balance toward the gain section as you turn it up, but there's something wrong someplace in the gain section, so you're essentially fading in a dead or weak signal.

What I'd do is just resolder every component in the drive section (all of the components surrounding IC1B all the way to the input of IC2A). Even after building tons of pedals I still get an occasional cold joint once in awhile, an unexplainable issue with the pedal that is suddenly fixed when I touch all of the joints with the iron and a tiny bit of fresh solder. Other than that, maybe try replacing the diodes and the IC1 opamp (assuming they're all socketed).

Hope that helps!

[nate77]

Thanks Kevin. Your synopses of what's going on with the dual gang is what I had assumed. I'll give everything some fresh solder and see what's up. I know that as much as we'd like it to be sometimes, it's almost never the components. Thanks for your time man. Always appreciated.

[nate77]

So I've resoldered every component, replaced ic1 and the gain pot and I still have the same issue. I'm at a loss. I'm going to measure all the ic pins and such later and see what's up. I'll post them as I have limited knowledge of what's happening in the circuit.