We found this circuit in an Electronics Now magazine from June 1995. The transformer has a primary according to the network and a secondary of 6 to 9 V with 100 mA.
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...