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In the Forum: Audio Discussions
In the Thread: How to get a LOT of SET power.

Post Subject: Non-linear electric chairPosted by N-set on: 5/6/2011

I've been pushing this intellectual excersise (masturbation?) of solving Romy's constraints on a powerfull bass SE amp.
Thanks to Stephie Bee the humanity have now a decent model of GU81M, so before electro-cutting
onself, one can see if the electrocution will be linear. Who wants to be electocuted by an ugly, distorting
electric chair?

Below are some simulation outputs for 6E5P(triode)-DC-GU81M. The input is 2Vrms for plots. The out power 185+W into 1 Ohm.
The opearion is A1, there is enough gain, big 6E5P!moreover it seems, at least in simulations, that 6E5P can drive Gu81M into a mild A2 too.
Very strangely, the higher the frequency, the uglier the simulated spectrum. The inductord are 100H driver load
and 130H OPT primary. The load GU81M wanted to see is strangely 4k.

The waveform at 1 Ohm load 20Hz. The charging effect I've mentioned is clearly visible at the first couple of peaks:

The FFT of the waveform above:

The same at 50Hz. Really ugly. What do the dips mean?

Pentode infierno at 100Hz:

This is all assuming the ideal PS, the ideal transformer/choke, etc. One observation is that the higher
order harmonics would be cut by the OPT.

How this all relates to the Sound (if at all)??? I have no idea. It all looks ugly to me.
How sensitive is the ear to the distortion at ULF? No idea. F-M curves suggest more than to
MF or HF distorion as the sesnitivity of the ear to ULF harmonics is higher than to the fundamental
(unless I mess something up).
Is it worth trying based on the above curves? No idea. Would rather see a PSET with 2x250W triodes,
but the only candidate which comes to my mind is 212E at the cost superpassing
all the tube price idiocy out there.

Cheers,
N-set

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