Morgan Jones does a better job on feedback than Rozenblit... - Dave VH

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Morgan Jones does a better job on feedback than Rozenblit...

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Posted by Dave VH on February 3, 2000 at 16:42:43

In Reply to: Re: How can you tell if there is negative feedback in a circuit drawing?? posted by neilium on February 3, 2000 at 16:06:16:

in his book "Valve Amplifiers." I have both, but I hadn't taken time to read them before posting. I just looked into them briefly, and I now know the basics of the difference between local feedback within a stage and global negative feedback between the speaker output of the tranny and the input stage. Rozenblit and Jones are not SET fans, and there are no SET-focused tube design books for us marginal techies.

I know that Gordon Rankin used 3dB NF in his now-discontinued "Junior" EL84 SE amp, and that Steve Sammet of SAS Audio uses at least 3dB of feedback in his super low-noise EL34, 6550 and KT88 SE amps. It seems that Antique Sound uses lots of global negative feedback (20dB plus) in all of their amps, compared to the Wright, Welborne, Wavelength, etc.'s zero feedback designs.

What are the factors that allow good sound without feedback? Sammet calls his variable feedback "variable" damping, and lets the user drop it to about 3db, but not zero. Are true triodes better for ZF designs?

Dave van Harn

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Follow Ups Full Thread

Topic - How can you tell if there is negative feedback in a circuit drawing?? - Dave VH 15:02:52 02/03/00 (7)

Re: How can you tell if there is negative feedback in a circuit drawing?? - neilium 16:06:16 02/03/00 (5)

Morgan Jones does a better job on feedback than Rozenblit... - Dave VH 16:42:43 02/03/00 (4)

Dave, - Victor Khomenko 18:23:37 02/03/00 (3)

For a DIY'er with only rudimentary circuit knowledge, can one... - Dave VH 08:10:29 02/04/00 (1)

Yes, yes, no, yes, no..... - Victor Khomenko 09:06:14 02/04/00 (0)

Re: A Q to an expert (Victor, as well as others) - PÃ¤r 22:53:43 02/03/00 (0)

Re: How can you tell if there is negative feedback in a circuit drawing?? - Tom Â§. 15:36:03 02/03/00 (0)

Follow Ups

Morgan Jones does a better job on feedback than Rozenblit... - Dave VH 16:42:43 02/03/00 (4)

Dave, - Victor Khomenko 18:23:37 02/03/00 (3)

For a DIY'er with only rudimentary circuit knowledge, can one... - Dave VH 08:10:29 02/04/00 (1)

Yes, yes, no, yes, no..... - Victor Khomenko 09:06:14 02/04/00 (0)

Re: A Q to an expert (Victor, as well as others) - PÃ¤r 22:53:43 02/03/00 (0)

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