Wah pedal Mods....

[Ground Control]

I just bought Craig Andertons's "DIY Projects for Guitarists" hoping to see the "scratchless volume pedal mod" done with the photo-conductor (CLM6000).

...but I must have a newer version (c1995), and this mod now uses a CA3080 OTA. I'm bummed. Does anyone have a copy of the old article with the LDR in it??  I want to see how this circuit works before I start a wah pedal mod.

GC

[Transmogrifox]

I don't have the copy of that, but if all you want ultimately is a scratchless volume pedal with an LDR, check out Morley's little alligator:

http://www.morleypedals.com/pla.pdf


Just use a simple opamp or transistor unity gain follower to modulate R3.  They use a kind of optical blocking thing to block light from the LDR, but if using a CLM6000, just expriment with some resistor values on the LED side to get the range right, then this should work well.