Big Muff Pi blend pot query...

Discussion in 'Effects [BG]' started by Beav, Sep 13, 2005.

  1. Beav

    Beav Graphics Whore

    Jul 17, 2003
    Middle Tennessee
    Designer: Beav's Graphics
    I'm thinking about installing a blend pot on my Muff. I've seen where a couple of people have done this, but it looked fairly complex. Would it be possible to wire one like this? What big concept am I missing?

  2. That might work, but there should probably be a connection to ground, as shown here...

    The concept that might cause a problem is "feedback"... signal feedback from the output of the muff circuit back into the input. If that happens, it will not sound like the clean signal is being blended with the muff signal. But, there is a chance that you might actually like how it sounds (total sonic annihilation, anyone?).

    If you want to accentuate the feedback effect, just use a single pot instead of a dual blend-pot... clean signal to one outside lug, muff output to the other outside lug, center lug to output. Also use a small value pot, maybe try ~100K.

    If you want to prevent the feedback effect, a large value single pot (at least 1M) wired like I just described might work. But, there's a better chance that a 500K or 1M dual blend-pot set-up like in that stew-mac link, above, might do the trick.

    If pots don't work, the next step up would be to put a simple buffer circuit in parallel with the muff circuit. There is a really good description here...
    ... just replace the send/return jacks with wires that go to the input/output of the muff circuit.

    I've also built a dedicated pedal with the send/return jacks so I can do the clean blend with any pedal I want. There's some more pics on my web site if you're interested. :cool:

    ~ Charlie