This is the traditional audio preamp configuration with the National Semiconductor LM382. The circuit has good gain and can be used with magnetic pickups or from signals from an auxiliary input.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...