weird wah problem

[pinkjimiphoton]

so... i gotta cheap crybaby with some other crap in a "lot" off fleabay.

the wah needed some work, so i set about messing with it last nite. had to add a new switch (added a somewhat melted dpdt from one of my first builds..only one side works, but it's enough) and new jacks, and a new pressure thingy for the rack... i cut it out of  one of them translucent orangish plastic prescription bottles, worked great!

but...here's the thing.

the wah works... sounds great...

but the pot only goes up about 1/2 way, and then sounds like it abruptly goes to the heel down position!! from heel down to about half way, sounds great. beyond that, and it ... i dunno what the heck it's doing, but it's not right!!

the voltages all seem ok, and all... i don't have another pot around to try without cannibalizing another one.

do you think it's the pot, or is there something else i should look at?

i tried using search, and as always found a plethora of cool info, but nothing directly relating to this little problem.

can someone buy old pinkster a clue?

[Paul Marossy]

Sounds like the pot might be wired wrong. Is this a newer GCB-95 type wah or some old one that's hand wired?

[pinkjimiphoton]

it's an older gcb 95, from around 92 or so. the pot is wired, not on a pcb/connector like some of the newer one.

pot reads about 118k across the outside terminals.

tried rewiring it, the wiring is definitely right this way. any other ways, tho amusing, are pretty useless.

any other ideas paul?

[Paul Marossy]

Bad pot? If everything was working as it should be, this shouldn't be happening.

[pinkjimiphoton]

that was it.
i tried a couple other pots of various resistances, and it worked fine.
so i took it out, and was gonna replace it when i noticed it looked like someone had monkeyed with it before.
and they had!
they put the back shell cover on so that the "stop" was in the wrong place, so the dead ends of the sweep were in the middle.
took a little playing with to get it right, but that was it. once it was good, a couple careful pinches with the old vice grips and we have achieved wah-age!
thanks paul
rock on bro

[Paul Marossy]

Aha! Cool, glad you got it worked out. 

[joegagan]

[pinkjimiphoton]

thanks joe!!
i was lucky, got it back together right.. when whomever had it before did it, they put the back cover on 180 degrees "out of phase"... i just turned it til the sweep was good, and tightened it down, all good!!
nice wah... i may keep this one.

it's neat, i watched the video, and it's almost exactly what i did... guess i was lucky!!