Found in 1980s Electronics Design, this circuit covers 4 decades of frequencies with a unique control. A multi-turn trimpot is used for fine adjustment. The frequency range depends on C1.
This circuit is from a 1967 RCA documentation. Components can be replaced with modern equivalents. The...
This 80's circuit uses a microcontroller programmed to generate various songs. The circuit can serve...
This amplifier, suggested by National Semiconductor, is characterized by its very high input...