Blew the dust off my '79 1987 JMP Head a few weeks ago. I hadn't used it in a long time because the original power rocker switch disintegrated some time ago and it took me a while to get a replacement from eBay and find time to wire it in. The switch replacement was no problem (other than reverse wiring it a few times as it was a 6-pin switch and the original was a 4-pin). Two things I noticed once it was done and I was testing. 1) There's a loud audible pop over the speakers when switching the new switch on and off. I can't honestly say if this was a problem before, as I rarely used this particular head. Is it likely this is the switch? Or could it be something to do with "Snubber caps"? 2) There is still some audible signal when the Vol I is on zero. And holy crap does the volume jump when you just tweak it a little from zero. Something is wrong, Do I just go for a new pot and wire it in, or is there some troubleshooting I can do here?