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RE: You've got it wrong

As Lew says, the "4-pole capacitor" does not in any way allow you to use a single supply for the output stage of a circlotron. The two supplies must be kept completely separate, and the 4-pole capacitor would not achieve this.

If you look at the pdf on the Jensen site, you can see that the two terminals marked Input- and Output- are essentially connected together, and likewise the two terminals marked Input+ and Output+ are essentially connected together. I say "essentially," because what is actually done is that Input- connects to the - plate of the capacitor foil itself, and Output- separately connects to the - plate of the foil. So there is a tiny amount of inductance and resistance in each of the wires from the capacitor Input- and Output- terminals to the foil, and that is the only sense in which Input- and Output- are not literally the same. Same for the + terminals. If there is any benefit at all from such a set-up, it is likely to be really tiny.

Regarding the quesion of whether the circlotron would work fine into a 500 ohm load without any storage capacitors at all, I think the answer is clearly no. With no storage capacitors on the output power supplies, they would then be providing supply voltages that were just full-wave-rectified sinewaves; i.e. the positive half cycle followed by an inverted negative half cycle (so a positive half cycle agaian), and so on. So the supply voltages would be dropping to zero 120 times per second, meaning that the audio output would be modulated with this 120Hz variation. Specifically, there would be short periods during each 1/120 second interval when the amplifier could output no audio signal at all. Whether the speaker impedance were 500 ohms or 8 ohms wouldn't really make any difference, as far as this is concerned.

Chris



Edits: 03/30/14 03/30/14

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