Just read Gary P's article .. - danlaudionut

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Just read Gary P's article ..

Posted by danlaudionut (A) on April 27, 2005 at 15:17:46

In Reply to: Let me try again ... posted by danlaudionut on April 27, 2005 at 14:32:49:

Russ
I just read this:
From
http://home.pacifier.com/~gpimm/47.htm

"The latest change to the design was the addition of a cathode bypass capacitor. As the purpose of this cap is to handle the error currents caused by tube mismatch, I placed the cap between the cathodes and the centertap of the output transformer. This connection closes the AC signal loop around the output stage without messing with the common mode rejection provided by the long tail biasing provided by the 1.5K cathode resistor. This change was made during a listening/BS session with Lynn Olson. We were discussing the differences between the ideal balanced P-P output stage and the real world where tubes do not really match. The idea were tossing around is the output stage really is 2 separate amplifiers. You have a perfectly balanced P-P, and a SE amp in parallel all sharing the same components. The SE amp represent the unbalance of the P-P circuit."

So I guess the ultra-path cap
with an unbypassed resistor
is the best of both worlds.

DanL

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Follow Ups Full Thread

Topic - Cathode Bias PP tail questions? - danlaudionut 10:55:29 04/27/05 (14)

Re: Cathode Bias PP tail questions? - Gary P 19:57:55 04/27/05 (4)

Re: Cathode Bias PP tail questions? - MIchael Samra 17:43:52 04/28/05 (0)

Have you tried the WE connection on a CCS? - Mark Kelly 20:23:37 04/27/05 (2)

Re: Have you tried the WE connection on a CCS? - danlaudionut 20:41:29 04/27/05 (1)

Re: Have you tried the WE connection on a CCS? - Gary P 21:50:06 04/27/05 (0)

Haven't tried CCS. - Mark Kelly 16:38:36 04/27/05 (0)

For an 845, why not use fixed bias? - Russ57 11:49:30 04/27/05 (7)

Re: For an 845, why not use fixed bias? - MIchael Samra 17:19:03 04/28/05 (0)

Let me try again ... - danlaudionut 14:32:49 04/27/05 (1)

Just read Gary P's article .. - danlaudionut 04/27/0515:17:46 04/27/05 (0)

Because Fixed Bias.................. - drlowmu 13:45:13 04/27/05 (2)

Re: Because Fixed Bias.................. - Russ57 15:32:32 04/27/05 (1)

Re: Because Fixed Bias.................. - drlowmu 10:42:59 05/2/05 (0)

Re: For an 845, why not use fixed bias? - kadyquil2 13:14:31 04/27/05 (0)

Follow Ups

Just read Gary P's article .. - danlaudionut 04/27/0515:17:46 04/27/05 (0)

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