• 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.

EL82 - PL82 PP amplifier

No, it really isn't. In each and every case we have to look into the datasheet, as for some tubes the parallel and the series heater variants indeed are identical (ECL82 ~ PCL82 ~ UCL82, ECL86 ~ PCL86, EL36 ~ PL36 and many others), in others they aren't, as the series tubes are designed just to cope with low supply voltages also (from ~100 Vdc on).
Probably the most puzzling example is ECL83 vs. PCL83: Same pentodes, but very (!) different triodes.
Best regards!
 
6п18п
I have built and tested several amplifiers with EL86 (6P43P-E), which is quite close to EL82.
With 300 V supply voltage and 5k UL-output transformer, more than 20 W is possible to get. With 250 V and 4k UL-OPT, it is possible to have some 15 W.

This is my test circuit, a Dynaco-style pentode amplifier/cathodyne phase inverter with 6F12P triode pentode.
Hello i want to build your amp with 6P43P if you can help me with some answers:

P3 100K you change gain or set voltage on G2?
What is the input sensitivity for P max. ?

Thanks