Found in documentation from the 1990s, it uses a sound effects integrated circuit, the SN7677 from Texas Instruments. Unusual component these days.
This circuit is from a technical documentation from Texas Instruments from 1978. In it we have the...
We found this circuit in a publication with experiments with operational amplifiers from 1973. The...
Using a varactor or varicap, this 1969 Electronics World circuit has a modulation range from 75...