Home GuitarPCB Forum Forum Rules SWAH Filter Sweep Mod

  • This topic has 2 replies, 2 voices, and was last updated 2 years ago by Anonymous.
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  • #22950
    Anonymous
    Inactive

    I’m about to build the SWAH Auto-Wah.  I was wondering if there is a mod for this pedal that would enable me to change the direction of the filter sweep?  So that instead of the wah descending, making an “eeewww” sound, it could also make an ascending sweep, creating a “wwweee” sound.   Having a “Sweep Direction” switch might be a really cool feature!

    #23008
    Barry
    Keymaster

    There is no mod that I am aware of.

    To switch the autowah, you need to get the inverse signal of the rectified envelope that is the control signal, which goes to the input of a VCA. You have to switch the inversion in/out. The control signal is coming from the emitter of Q2 – Q3 through R26 into the VCA. Trying to change that entire transistor pair setup into an inverting amp would be hard. Not impossible but a lot of modding.

    #23014
    Anonymous
    Inactive

    Interesting.  Thanks!

     

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