This variable frequency circuit was found in a Popular Electronics from the 90s. The circuit outputs to a small speaker and can be powered by voltages as low as 3 V.
This oscillator circuit with two transistors is from a 1965 documentation. The circuit is of the...
This circuit was obtained in an old documentation, but it is still current by the used components....
This guitar effect pedal was found in 1982 documentation. The circuit can be easily assembled with...