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    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

Sweep tubes in Push-Pull-Parallel

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Good morning everyone,
I’m having thoughts of doing a sweep tube amp in Push-Pull-Parallel. I’m planning 500vdc on the plates and 150-180vdc on the screens.
My thoughts were to go “capless” as I have eight 6HJ5’s. I have not found any curves on the net for this tube or it’s close relative the 6HD5. The plate dissipation on this tube is 24 watts, my thought was to have them idle at 30ma/tube (15w/tube). I have a 1.8K ohm P-P 150w transformer at my disposal. Do you think the transformer impedance is about right for what I am planning? It seems on diyAudio, 3.3K P-P is used quite a bit for Push-Pull sweep tubes, so I am assuming that 1.8K P-P is a good value for Push-Pull-Parallel.

Thanks,
Ray
 
Should work well with screen drive too. Transconductance and triode mu are similar to 6HB5/21HB5, so you could start with that one. You'll want grid, screen, plate stoppers when paralleling such tubes - the traditional plate stopper is a 50 Ohm resistor with 4-5 turns of wire wrapped on it (L in parallel with R).
 
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