This transistor class B 5 W amplifier was found in a 1969 Mullard documentation. The transistors are from that time, and modern equivalents may eventually be used.
This circuit is from 1968 documentation. We can assemble it with more modern components such as a...
Found in a 90s Silicon Chip documentation this circuit is intended to protect a speaker system in...
The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from...