Re: I was thinking

Posted by Jim McShane (D) on December 10, 2006 at 15:06:58

In Reply to: I was thinking posted by sser2 on December 10, 2006 at 14:51:29:

But in a push-pull amp operating in class A the signal has been inverted in 1/2 of the output section, just like it would be in any push-pull amp.

So while both sections pass signal full time, one output section is "pushing" while the other half is "pulling". Clearly if the amount of "push" and "pull" isn't equal or nearly so, there will be distortion. And the amount of "push" and "pull" is at least partially a function of the tube Gm.

Did I make that clear with my explanation? If not I'll try again.

Oh, as an aside that may help, while we often lapse into calling the phase inverter a "phase splitter" that's not the case at all. The signal is not split, rather it is inverted 180 degrees. So one of the phase inverter's two outputs is not inverted and is applied to one side of the output, the other is inverted and is applied to the remaining side of the output. So when the output stage gets signal applied one side "pushes" the signal, the other "pulls".

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Follow Ups Full Thread

Topic - Output Tubes: Matching for Plate Current / Transconductance - rontokyo 05:10:33 12/09/06 (16)

If they are new tubes, - sser2 16:08:34 12/09/06 (6)

Re: If they are new tubes, - Jim McShane 09:19:16 12/10/06 (5)

Thanks for the correction. - sser2 13:05:30 12/10/06 (4)

Re: Thanks for the correction. - Jim McShane 14:01:31 12/10/06 (3)

I was thinking - sser2 14:51:29 12/10/06 (2)

Re: I was thinking - Jim McShane 15:06:58 12/10/06 (1)

I see. - sser2 16:15:25 12/10/06 (0)

so, hopefully, this explains why ... - Thom 08:47:02 12/09/06 (1)

Re: so, hopefully, this explains why ... - Jim McShane 10:48:42 12/11/06 (0)

Re: Output Tubes: Matching for Plate Current / Transconductance - lovetube 05:36:38 12/09/06 (6)

Re: Output Tubes: Matching for Plate Current / Transconductance - jcoe 14:38:41 12/09/06 (0)

Yes, I understand that it's important. But - rontokyo 05:44:43 12/09/06 (4)

Re: Yes, I understand that it's important. But - Jim McShane 06:39:21 12/09/06 (3)

Doesn't it depend on how the tubes are going to be used? - Ray Moth 13:42:40 12/09/06 (2)

Re: Doesn't it depend on how the tubes are going to be used? - Jim McShane 15:51:11 12/09/06 (0)

Clarification - Ray Moth 13:51:36 12/09/06 (0)

Follow Ups

Re: I was thinking - Jim McShane 15:06:58 12/10/06 (1)

I see. - sser2 16:15:25 12/10/06 (0)

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