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.
This 80's circuit has been winning. It is a 1 000 gain sample and hold circuit and an offset...
The purpose of this 1-transistor amplifier is to allow the use of a milliammeter in an application...
We found this circuit in an old General Electric documentation. In fact, PUTs are not common...