WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Both have a medium mu triode and a sharp cut off pentode , BUT
the triode's average plate characteristics are very different , and the
pentode's not so much , but are different too .