This Mullard circuit was found in a 1969 documentation. It uses complementary transistors on the output and does not need a transformer. The bandwidth goes from 100 to 20 000 Hz.
This circuit is used in transceivers, enabling input selection by diode switching through polarity...
This configuration was found in an American publication from the 90s. Operators admit equivalents just...
This circuit was found in an Italian magazine Elettronica Prática of 1977. The transistors can be...