The integrated circuit and configuration are uncommon. However, the sound quality is good. The circuit is from the 1983 Intersil Databook. The output transistors must be provided with heat sinks.
We found this circuit in an old American documentation. SCRs can be modern equivalent types. The...
We found this circuit in a 1990 documentation. The operational amplifiers are type 741 and the LED is...
This fast-acting circuit uses a 555. We found it in the November 1992 Radio Electronics magazine. The...