Found in a 1947 publication, this circuit uses 4 parallel/push-pull tuber in the output stage. The circuit employs dual power supply with two rectifier tubes.
This circuit was obtained from a Radio & Electronics Constructor from March 1976. The magazine no...
This buffered version of the previous circuit appeared in an article in the September 1989 Radio...
This circuit was found in a 1968’s publication and uses germanium transistors. Equivalents can be...