I’m doing a repair job on an old Japanese spring reverb. The main mix pot is really janky so I opened it up thinking I could replace it, but it’s something I’ve never seen before. There are the normal three pints at the bottom, but it looks like there’s a small board integrated on the top side with a wire coming out.
Anybody have a clue what this could be? Doubt I’ll be able to find an exact replacement, but maybe I could figure out a bodge if I knew what this output (input?) was.
Are these odd pots illuminated on the face?
You got a lot of ‘board’ wired on to stop pots cracking the nice plastic face. A way of mounting lug pots on a breadboard. It would be grounded like a case.
Have you a schematic?
Good thought, but it’s not a light. My thought was grounding as well. I guess I’ll just take the whole board off and see where the wire leads!
Could It be a crossover patch on the pot to provide an inverse resistance level elsewhere?
And let’s be honest, that board was always coming off!
Centre-tapped potentiometer?
I found something similar-looking on eBay
I also found Potentiometer with four terminals “used to alter the resistance curve for special applications”.
Perhaps you can bung in any 50k pot to get the unit working ignoring the yellow wire, so not the original taper. Best of luck.
yes, that’s what it looks like to me! good find!
A bit of a mention of center tapped pots here:
So pull out the knackered 4-pin pot, bung in a fresh 3-pin pot to get the reverb working.
Then clean up the 4-pin pot to make something interesting…
Can we see the front panel, please?
