Found in a Philips' 1968 documentation, this circuit is slightly different from the previous one. The components are also from the era, and modern equivalents can be used.
This amplifier from 100 to 150mW was found in a Japanese documentation from 1967. The circuit uses...
This circuit is from a manual of JFETs and can be implemented with the BF245 and for the bipolar...
This source of some amps for voltages up to 40 V was found in an Italian magazine Elettronica...