'Nother build report - Running Wah

[RickL]

I found it in the guitar effects section in projects here: http://members.shaw.ca/roma/

It's a similar idea to the Phozer, a wah with an LFO. Beware that the layout posted has errors. It took me two days of occational fiddling to find the last one.

It sounds pretty good although there's not much range in the LFO. It would be nice if it went both slower and faster but I think it's a limitation of the LFO design. If you want more resonance on the filter add a capacitor from the source of the FET (note it's an NFET) to ground. I used a switch to choose between no cap, 0.22uF and 1uF. Lower and higher values should also work.

Since the FET acts as a variable resistance it would be easy enough to use a switch to choose the FET or a pot. The pot could be panel mounted for fixed wah sounds or in a wah shell for traditional wahing.

[ExpAnonColin]

I built one with the a different LFO and a LDR based setup on the original wah schem.  It sounded OK but I had the same range problems, mostly due to the photoresistor I was using.

-Colin