Getting extremes of a Wah without using an inductor?

Started by Bungleigh, December 22, 2015, 10:05:10 AM

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Bungleigh

Hello,

I'd like to be able to add a switch to a box that, when engaged, provides the EQ filtering effect of a wah when it is at the nasally/treble heavy extreme of the sweep. I am not entirely sure how a wah pedal works, but I *think* the value across the inductor changes as the foot part of the build moves the pot. I'm thinking it would be cool to play with a wah schematic and try to reduce it to just the section that filters the signal and setting it to where I want it with a trim pot or something along those lines.

Or if I'm headed entirely in a fruitless direction, would it bet a better time investment to look at EQ pedal builds? I've never owned an EQ pedal, just a WAH and when I used it I would only use it at either the nasally end or the throaty end. If I could just have those two options with switches I would be super happy.

But if the inductor is a necessary component to getting those sounds, it would probably save me a lot of headache if anyone could let me know. :)

Cozybuilder

#1
Heres an excellent article by RG explaining inductor wah pedals. At the bottom of the article is a little about inductorless wahs, you should be able to get some ideas from this:

http://www.geofex.com/article_folders/wahpedl/wahped.htm
Some people drink from the fountain of knowledge, others just gargle.

Transmogrifox

This one is an easy circuit to build, and probably does "waht" you "wahnt" (please excuse me if you can't bear terrible puns).
http://4.bp.blogspot.com/-p5zwwQmEPcI/VUVnU52N2RI/AAAAAAAAOi0/X8EEncbtE9g/s1600/Colorsound_Wah_Schematic_Stock.gif

The pot could be replaced with a fixed resistor or a trim pot (or a knob on top of the box).

With the inductor wah, you could do the same thing with a pair of fixed resistors, or a trim pot or knob.

I can't point you to a layout that does exactly what you want, but with a little help from google you can find a lot of layouts for the Colorsound inductorless wah as well as modifications.  You can build it exactly per layout and then you only have to experiment with where you want it to be "stuck", then solder in a resistor to take place of the pot wiring.

If you're ok with doing your own layout and only need a circuit for inspiration, I also experimented with an active circuit to emulate the sound of the classic inductor wah.  That way you can get closer to the subtle characteristics of a "stuck wah":
http://cackleberrypines.net/transmogrifox/TransmogriNotes/skwah/
trans·mog·ri·fy
tr.v. trans·mog·ri·fied, trans·mog·ri·fy·ing, trans·mog·ri·fies To change into a different shape or form, especially one that is fantastic or bizarre.