This 8 W amplifier with germanium transistors was found in a Japanese documentation from 1967. The circuit is of the commercial type and is powered by two 12 V batteries or by a symmetrical source.
This circuit can work with almost any JFET. The circuit is from an Electronics Now from April...
This physical line servo control uses components that are not currently common. The circuit is from...
This circuit was found in a British documentation from 1969. It can be implemented with modern...