This simple audio generator with the 741 was found in a 90sTexas Instruments. The circuit generates sinusoidal signals from 15 Hz to 150 kHz in 4 bands, as shown in the diagram.
This circuit was found in Japanese documentation from the 1960s. It is a commercial circuit with...
This tone control was obtained in the Audio Handbook of the National Semiconductor of 1977. The...
This simple receiver for listening on the phone was obtained in a 1960 documentation. The circuit is...