Optical potentiometer (CB22159E)

This voltage-controlled potentiometer using an LDR was found in an English documentation. LDR is common and LED of any type.

Voltage and Current Regulator (CB5876E)
We find this circuit in a manual of the 80's own used components. The circuit provides an...
Fuzz effect (CB22080E)
This simple guitar distortion effect was found in a documentation from the 90's. The circuit is...
Operational Fuzz (CB11029E)
This circuit was obtained from Hands-On Electronics, an American magazine of January 1987. The...