Found in an American documentation from the 90s, this circuit has a configuration that has been extensively explored in other articles on this site. The FET can be the MPF102 or equivalent.
This circuit, found in an old magazine of the year 1968, uses a Power germanium transistor. This...
This sequential circuit with an optical coupler was found in a Popular Electronics from the 90s to...
This guitar effect circuit was found in a 2002 documentation. The circuit can be powered by a 9 V...