This circuit was found in a documentation from 1948. There are 5 valves with push-pull output. The source uses a transformer, and the indicated application is with turntables.
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...