This 12.5 W quasi-complementary amplifier was found in a 1969 General Electric publication. Note the high supply voltage. Transistors are common types at the time.
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...