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Hoffman Amps Forum image Author Topic: Newb question about cathodyne phase splitter  (Read 5156 times)

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Offline peacocksuit

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Newb question about cathodyne phase splitter
« on: October 30, 2023, 06:43:33 pm »
I'm a newcomer to tube amps and electronics in general. I'm gaining a good understanding of how these circuits fit together thanks to forums and uncle doug on YouTube.

I've drawn out a schematic for an amp which I was unable to find one for, the phase inverter section of this is pictured below.

I have a question in hoping someone will be able to a answer.

I understand that the signal is fed in an uninverted state (I'm going to call this A) into the grid of the first half of the dual triode. It becomes inverted (B) and fed into the grid of the second half of the dual triode via the anode. It's inverted once more (A again) when it leaves the second half of the dual triode via it's anode. An inverted signal also leaves via the cathode (B).

These 2 phases for the signal (A and B) go to each of the PP output tubes.

But if we back up a bit, the signal (B) left the first half of the dual triode and went via the blocking cap to the second grid. But, wasn't it also sent into the HT rail, AC and DC co existing in a conductor? When the signal leaves the second half of the dual triode it's A. Doesn't that mean the 2 anodes have put out opposing phases?




Offline pdf64

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Re: Newb question about cathodyne phase splitter
« Reply #1 on: October 30, 2023, 07:12:25 pm »
I can’t make head or tail of that circuit snippet.
It would be helpful to show the full circuit.
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Offline PRR

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Re: Newb question about cathodyne phase splitter
« Reply #2 on: November 16, 2023, 09:43:47 pm »
> Doesn't that mean the 2 anodes have put out opposing phases?

Usually, each gain stage has the opposite polarity, because gain stages usually invert.

Some signal does go into the power supply but swamped by a large capacitor on the supply rail.

No, I can't figure that drawing either.

 


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