SET amplifier Q
"Phil Allison"
** More testing with the FFT feature on a Rigol scope:
3H is dominant from about 9 watts through to 21 watts.
From 1watt to 4 watts, 2H dominates, then 4H, then 3H.
If load R is changed to 16 ohms, 2H dominates all the way.
2H cancellation is occurring over a fairly wide range, but it is not
complete.
I can swap the 6SN7 with almost no change.
** One final test result:
300Bs removed, 10:1 scope probe on grid pin, input 260mV rms to 6SN7.
2H = -24 dB = 6%
3H = -42dB = 0.8 %.
..... Phil
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