We found this circuit in the March 1980 Radio Electronics magazine. The circuit used is the HA2400 released at the time. The power supply must be symmetrical.
Using the NE5205 integrated circuit this circuit was found in the May 1987 issue of Radio...
This circuit was found in a 1980s American schematic. Transistors can be modern equivalents. The...
This circuit is from a 1972 Motorola publication. The used transistor can still be found, but it...