This circuit is from an Electronics World of 1968. The transistors are of the time and the power is supplied with a voltage of 40 V. The circuit is high fidelity.
We have dozens of similar projects in articles and circuits on this site. This is from Radio...
This circuit with an unusual configuration was found in the January 1974 issue of Radio...
This interesting circuit from 1967 documentation uses three series lamps to regulate the voltage...