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 basic configuration can be found in a lot of articles on this site. In this case, the relay...
Incandescent lamps, heaters and other resistive loads can be controlled by this circuit whose...
This setting is valid for other transconductance operational amplifiers. The circuit is from...