This circuit was found in a 1969 Mullard documentation. Used transistors can be replaced with modern equivalents. Output transistors may be BD135 and 136 with heatsinks.
This commercial circuit, sold under the designation H531 in Japan in the 1960s, used three...
This circuit is from the manual of the components used, from the 80s. The circuit is valid for...
Found in a 1980s American documentation, this circuit appears with variations elsewhere in this...