They’re a little hazardous due to the voltage but aren’t too difficult to make, as demonstrated by [M ircemk] whose version uses a recycled power pentode tube — which is how it showed up in ...

[Mikremk] demonstrates this with a simple but effective amplifier using a PCL82 triode-pentode. It’s a conventional tube amplifier circuit in which the triode is a preamplifier for the pentode ...

This report describes the fundamental differences between triode and pentode valves, and indicates how the performance of the latter type can be improved by applying ...