LED LDR wah pot replacement

[numpty]

I did a search about the above and found many questions but few useful answers.has anybody cracked a successful diy version, if so I would be very interested in comprehensive explanation on the electronics post LDR
as I understand the LDR does not replace the pot as it has a limited resistance range, but actuates electronics which takes the place of the rack and pinion / pot. I have seen the moreley schematics but don't understand them.

[Johan]

The Technology of Wah Pedals, at GEOFEX..about halfway down..

johan