This circuit has tone control, and its power depends on the supply voltage. The circuit is from the Philips integrated circuits manual from 1990.
This two-band receiver capable of tuning medium waves and the 3.5 to 10 MHz band was sold in Japan...
This circuit is from an American publication from 1975 and can use other operational amplifiers and...
This circuit is from an American 1964 documentation. Transistors of the time are used, but modern...