This circuit that generates a special sound was found in a Popular Electronics from the 90s. The base is the 555 and the transistors admit equivalents, and a power stage can be added.
Found in a European magazine from the 1980s, this circuit can amplify signals from 10 kHz up to...
The circuit in the figure uses the four current amplifiers of the LM3900 to generate a sawtooth signal...
This circuit is from a Radio Electronics magazine from August 1960. It is a commercial circuit for marine...