This circuit is from 2005 documentation. The integrated amplifier circuit must be mounted on a good heat sink and the speaker must be able to withstand the full power of the circuit.
This powerful amplifier with output in complementary symmetry is from an old documentation....
This transistorized oscillator, a modification of the Colpitts oscillator, was found in the...
Found in Popular Electronics from the 90s, this generator uses integrated circuits from that time....