This circuit was found in an Electronics World of 1966. It has a range of 5 to 25 000 Hz at 1 dB and the diagram includes the power supply.
The transformer for this project found in a 1986 documentation is an output type, found on old...
This circuit was found in a Popular Electronics from the 90s. It is based on components still...
We found this circuit in an American documentation from the 90's. The circuit makes use of general...