Moog ladder filter vs Wah

[Steve Ridley-MV]

Maplin do a kit for an auto-wah pedal based around a 2-pole
state variable VCF. It uses the LP output the Q cranked up 
to approximate to a bandpass, although it shouldn't be difficult
to get a bandpass output from it.  A simple envelope follower
takes care of the auto part.  The PCB was approx 3 last time 
I looked.  I built one into a Logan string synth a few years
ago to improve the brass sound, but I've never tried one with 
a guitar.

I've tried using a guitar through a Yamaha CS5, which can 
trigger the envelope off the external input.  The S&H modulation 
of filter cut-off sounded good too, but it would be even better 
if the S&H could be triggeded by notes played.  Putting a 
distortion circuit before the filter made things much fatter,
but it wrecked the envelope detection, so it would be worth
putting the distortion after the envelope follower input but
before the filter.

PAiA did a version of the 4700 specifically for use as a 
guitar processor (the  4700G?). It had no VCOs but used a
VCF, VCA, LFO etc - a modular "synth" for guitarists. 
Anyone out there ever used one?

And PLEASE don't destroy the Dunlop wah wah pedal. Even
if you don't want it you should be able to sell it, buy 
an empty pedal (Maplin?) and still have money left over, 

 
STEVE RIDLEY