This circuit with power MOSFETs was found in a 1980s Siliconix documentation. Equivalent MOSFETs can be used, as well as other transistors. Note the symmetric power supply.
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...