This 1967 Electronics World circuit is suitable for frequencies up to 1 MHz. The setting applies to virtually any junction FET.
This circuit is from an old documentation but still current for assembly. Just use BC548 instead...
Rumble is a low frequency noise between 25 and 200 Hz that appears in old turntables, affecting...
This circuit is from an American 1964 documentation. Transistors of the time are used, but modern...