This circuit generates sinusoidal signals between 300 and 3000 Hz. We find a 303 Circuits from the 90's. The operational ones are types with FET. The power supply must be symmetrical.
We found this circuit in a European publication from the 1970s. The transistors are made of...
The TAA131 used in this circuit is not very easy to find today, but an equivalent low power audio...
This circuit was suggested by National Semiconductor in its Linear Application Handbook. The...