This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Thursday, October 8, 2015

Escobedo Idiot Wah

Here's a quicky designed by Tim Escobedo. It's an inductor-less wah, and you can use either a pot or an LDR to control the effect. It's small enough to fit in a 1590a if you want a fixed wah in a small package.


Resonance switch is a SPST.

9 comments:

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    1. The schematic didn't really say a value for the LDR. Probably around 500k is a good place to start.

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  2. Can I use a pot instead of the resonance switch? Wich value?

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    1. A pot might not do much more than the switch as it's only grounding a small value cap. You'll have to experiment with the value.

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  3. Another stupid question:in which way can I turn this wah,which is basically a lo-pass filter,in a hi-pass filter? Is it possible?

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  4. Hi there! Sorry for my ignorance but what happens to the signal when the SPST is off? I know this not true bypass. But will my guitar sound be somehow similar when the fixed wah is off? Looks like the signal is going through some resistors, maybe I need to switch on my boost when the effect is off?

    thanks!

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    Replies
    1. The SPST isn't the bypass switch. It just adds some resonance. You'd wire bypass for this like you would most other effects. See the General Layout Notes for a diagram.

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    2. My bad! Now everything is clear. Thanks man!

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