This 7-tube circuit was obtained from an American publication in 1947. The circuit has a push-pull output with a source using a transformer.
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...