In the figure we have the typical circuit of a stereo decoder using the TBA450N integrated circuit. The circuit is from the 1976 Siemens manual. No information was given on the coils.
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...