Wah pedal mid-range bump

[LarryN]

In the lower range of my Crybaby wah, there is a point that breaks up the smoothness of the sweep. It's like a resonant peak that sticks out, that makes smooth rhythm playing difficult for me. Is there a mod that could smooth this out? The only mod I've done to the pedal is the 33k resistor to the inductor was replaced with a 68k. Thanks.

[Fret Wire]

Start out first with adjusting your pot rotation. Always good to check before you start the mods, and judging their effects.
http://www.happybob.com/marc/pot_adjustment_procedure.htm

[petemoore]

Mine does that too. Sometimes much too noticably.
 I thinking about adding tapering resistors from middle to one side of the pot...which side...how big a resistor...I'll probably start with 50k, one side then the other so I can try to tell what I'm actually doing to the sweep, see if I can get rid of some of the midhump and still get a nice usable range.
 The pot is what came in a VOX Wah, maybe it's getting a dead spot...it's not that old though.

[LarryN]

I had it in another wah, also. I don't think it's the pot. My pedal is pretty new. I think it's a circuit characteristic. I'm going to check out that link. Thanks.

[mrsage]

http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html

They suggest changing the value of the 1k5 resistor next to the 0.01uf "sweep cap" to somewhere between 1k8 and 2k7. I put a 2k2 in there and I like it. It boosts the midrange and smooths out the transition from heel to toe.