This circuit was found in a 1968’s Motorola documentation. The transistor is from that time. The load can have resistances between 10 and 80ohm.
The integrated circuit used in this regulator is not very common today. The circuit is from old...
This tone control was obtained in the Audio Handbook of the National Semiconductor of 1977. The...
We find this circuit in an American 1980s documentation. The circuit can still be assembled...