Found in an 1868 Mullard documentation this circuit has a dynamic range of 10 Hz to 25,000 Hz. Modern equivalent transistors can be used.
This setting appears multiple times on the site from different sources. This is from a 2000 manual...
This circuit is a shield for microcontrollers and computers drivind high power loads. In the...
July 13, 2015 - Mouser Electronics, Inc. today announced that it has signed a global distribution...