One for the Zappa fans out there. Great filter circuit that can do a whole range of cocked wah and more. We'll leave it to the very excellent Joe Gore to enlighten:
"The (Harmonic Energiser) has a deceiptively simple set of three controls: gain, filter cutoff frequency, and filter bandwidth. At moderate settings, it yields an assortment of stationary wah sounds. But you can also dial in ultra-narrow, ultra-resonant filtering beyond the range of most wahs. And these edgy filters burst into overdrive in weird, unpredictable ways. User beware."
Yeah, what he said, except the FuzzDog incarnation gives you the option of an external volume control too, as tweaking the filter can alter the perceived output level.
If you opt for vertical-mount pots they have round shafts, so you'll need knobs that fix with a set screw. Feel free to wire in 'normal' pots if you prefer a splined shaft.
Kit includes: PCB, all components, hook-up wire, 3PDT footswitch for true bypass, high quality jack sockets, DC socket, battery snap, LED. Enclosure (pre-drilled) is optional and will not take a battery. Does not include knobs.
PCB size: 50 x 40mm
Knobs required: 3/4
Direct-Connect compatible (4-way)
Download the INSTRUCTION PDF