This circuit is from a 1968 Motorola power circuit manual. The circuit uses transistors of the time. The passing band is 45 Hz to 100 kHz.
Using an operational amplifier, the figure shows how to convert the waveform to low frequency...
This is the power step of the previous circuit. Output transistors must be mounted on good heat...
The UM3562 integrated circuit (not very easy to find) synthesizes three types of sound that...