True, P-P class A is not a real good analogy here.
What I meant is that with the tube currents not tracking, you get the more curved end of one characteristic played off again the less curved end of the other characteristic. Which will cancel the 2nd harmonic if configured correctly, but not the odd harmonics. Both currents must track on the same characteristic curve to get full cancellation via the neg. feedback. So crossed feedbacks would be the place to start for a fancier design.
What I meant is that with the tube currents not tracking, you get the more curved end of one characteristic played off again the less curved end of the other characteristic. Which will cancel the 2nd harmonic if configured correctly, but not the odd harmonics. Both currents must track on the same characteristic curve to get full cancellation via the neg. feedback. So crossed feedbacks would be the place to start for a fancier design.
Interesting UL configuration, suspect it can be replaced with a high voltage mosfet (IRF820)
6550/KT88/EL34 single ended amplifier
6550/KT88/EL34 single ended amplifier
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The EL34 plate voltage goes well above the B+ for half the audio cycle. This will make the 6CG7 unable to act as a follower for the screen drive since it only has B+ available at best.
One can either try to bootstrap up the B+ going to the 6CG7, or use an R divider for the 6CG7 grid from between the EL34 plate V and 0 V instead. (the 6CG7 plate supplied from the EL34 plate then.) This reducing type divider works well for TV Sweep type output tubes since they use a lower screen V.
One can either try to bootstrap up the B+ going to the 6CG7, or use an R divider for the 6CG7 grid from between the EL34 plate V and 0 V instead. (the 6CG7 plate supplied from the EL34 plate then.) This reducing type divider works well for TV Sweep type output tubes since they use a lower screen V.
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