MoWah heel click help

[Anonymous]

Hello GuitarPCB Community!

I am in the process of building a mowah pedal. Given the amount of customization options available, I decided to begin by building it on a prototype board (I have the main pot mounted in the pedal and wired to the board). I’m using a Dunlop red Fasel and vox/crybaby style enclosure. In operation the heel click happens far into the pedal travel- like 1/3 of the way in, and this is significantly limiting the overall control of the pedal (it doesn’t seem like heel pads would be a good solution). The trim pot doesn’t seem to be changing the position of the heel click, nor does increasing the value of R9 (I went up to 56k and noticed no difference). I have also tried to adjust the mechanical engagement range on the pot to push the heel click back as far as possible. Any suggestions on other things to try?

Thanks!
-Colin

[Billy]

Check all the mechanical parts on the enclosure especially the pivoting part

It’s very difficult to trace your circuit on a breadboard hard to see values etc but if you’ve done everything advised in the build doc then I’d be looking at the enclosure mechanisms

[Anonymous]

When I built my super wah, I experimented with several issues.  The range of the pot can be adjusted by changing the start point of the rotation by changing the setting of the tooth.  It can also be limited on the bottom (heel) range by adding a resistor between lug 1 of the pot and ground.

The overall range of the wah is easily adjusted by changing cap values.  I used a Roto-Tone to provide a selection of 4 ranges.

Perhaps these ideas will assist you.

[Anonymous]

Thanks both of you for the suggestions! The resistor between the pot and ground as a way to limit the heel range makes perfect sense and is a great idea I had not tried yet. However, to my surprise even a 50k resistor had no effect on the position of the heel (I left the pedal right at the point of heel click while adding the resistor to make sure). I will keep experimenting on both the mechanical and electrical side to see if I can figure anything out, but in the mean time, any additional thoughts would be welcome.

[Anonymous]

I would suggest you actually populate the GPCB MOWAH circuit board and install it into a pedal shell with a proper wah pot.  There may be subtle changes in the overall circuit performance that give different results.

[Author]

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