This circuit provides 2.5 W of power with 6 V supply and 4-ohm speaker. We found it in the Radio Electronics magazine of April 1990.
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...