This fuzz effect for guitars was found in an American 1980s documentation. The transistors may be the BC549 and should be battery powered for noise sensitivity. Diodes are commonly used.
This circuit is from an 80's documentation. The BC108 can be replaced by the BC548 and the 2N3055...
This circuit was found in a 73 amateur radio magazine from the 90s. An LED extends the scale from 0...
The diodes are for general use and the transistors also in this Exclusive-OR circuit. The circuit may...