Phase splitter idea

[rman]

Hi all.

Just an idea for consideration.
A high gain stage, phase splitter if you have the extra B+ voltage or for low voltage tubes. No, the top tube is not a cathode follower.

[Sch3mat1c]

Uh, do the nodes cross or join? Unmarked four way intersections are ambiguous.

In any case, if you're wiring it the way I think you intend to, I'm afraid the top tube is indeed a cathode follower.

Tim

[godfrey]

Either way, it doesn't look like a phase splitter.
The electrolytic capacitor connected between the outputs....

[Geek]

Heya Rman,

What Godfrey said... you have that electrolytic shorting your outputs.

Perhaps a straight SRPP version of this? You're not hammering any lines or anything...

*something seems vaguely familiar... did Broskie touch on this?*

Cheers!

[kavermei]

I don't think your circuit could possibly work

[rman]

Here is the corrected version. I know it works because I have an amp with this as an output stage. It is single ended in operation. Hi Greg, you are right about the Broskie connection. He showed it as a rough idea that I fleshed out and made work. I was looking at it again to remind myself why the top tube is not a cathode follower but indeed a voltage amplifier when I thought it could be made into a phase splitter. I am not planning to build a push pull amp so I thought I would just throw it out there.

I am trying to get a shop power supply off ebay. If I get it, I will wire this up and see how it works.

Cheers.
Rolf.

[rman]

Thank's guys for pointing out my error. I was rushing my cut and paste job in ms paint.

Broskie's name for this as an output stage, with a transformer where the load resistor is in my corrected schematic, was "Accordion amplifier". Maybe I subconsciously associated accordion with concertina, which is, of course, a kind of accordion. It is sort of similar except instead of one tube and two load resistors and no gain, it has two tubes, one load resistor, and lots of gain! It is sort of like an inside out concertina!

Cheers/

[godfrey]

Um, sorry, the top one's still a cathode follower.

Here's an article I found about the accordian:
The Tube CAD Journal: The Accordion Amplifier: A new single-ended topology

The top and bottom tubes need to be separately driven e.g. by an interstage transformer with two secondaries.

[Svein_B]

I do not think the top is a cathode follower, as it will produce gain (I believe).
When working as intended the middle of the RL will be at a constant level with no AC.

The Accordian as described by Broskie may serve a purpose as a power stage, but whether it has any merit as a phase splitter/driver compared to say a gain stage and concertina remains to be seen.


The Tube CAD Journal: The Accordion Amplifier: A new single-ended topology

The top and bottom are driven by the same signal (with caps to block DC) and should not need an interstage Xformer.

Svein.

[Sch3mat1c]

Originally Posted by Svein_B

I do not think the top is a cathode follower, as it will produce gain (I believe).
When working as intended the middle of the RL will be at a constant level with no AC.

No, and no. Does Kirchoff mean anything to you?

The circuit would work better if RL were split into a CF-to-GND component and a plate-to-B+ component, that way the AC voltage on each would be only the individual output, not the total.

The Accordian as described by Broskie may serve a purpose as a power stage, but whether it has any merit as a phase splitter/driver compared to say a gain stage and concertina remains to be seen.

http://www.tubecad.com/articles_2001...ifier/img5.gif

What the hell. Connecting two tubes in series has absolutely no merit. You can do it in one, without wasting the transformer required to drive the top tube!

Tim