This circuit is from a 1969 EEE magazine. The transistors are from that time, but the circuit can be implemented with modern equivalents, such as 2N2646 for Q3.
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...