Re: What about....

Posted by mqracing (M) on August 17, 2001 at 20:46:43

In Reply to: Re: What about.... posted by steve jones on August 17, 2001 at 10:02:56:

Steve: Hello. Your post captured my attention... for a long time I have been recommending that folks run tubes "nice and easy" for great sound quality.

to respond to some of your text;

< >

I have a parafeed circuit designed by Bill Petrowsky that is in the public domain. It runs at the points you list below.

< >

my unscientific gut level feel is that it has much to do with the low power operating points. I was mesmerized from day one when I saw in print sets of operating points picked out by the folks at Stereo Sound as their preferred points.... 845's at 430 volts and 62 mils... the 211 tube at 480 volts and 40 mils....

figured that either these guys were really on to something or else they just missed by a solar system or two. When I heard a friend's amp built around the 845 points... then I heard the beauty... so that these have had a major influence on my work and my designs.

> > The WE spec sheet list a nice point at 250V B+ @ 40mA, into a 3K load for 4 watts out. Almost perfect for an extended voltage C4S and a pair of TJ Meshies parafed. < <

this is exactly what bill Petrowsky's design is based on. If you look on the WE sheets this set of operating points is amongst the lowest distortion points published in their data sets.

I have long suspected that power and beauty are "inversely related".

MSL

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Follow Ups Full Thread

Topic - How many of you prefer the sound of 300Bs over 2a3's? - Briner 21:05:05 08/16/01 (27)

Re: How many of you prefer the sound of 300Bs over 2a3's? - groverg 04:18:43 08/18/01 (1)

Re: How many of you prefer the sound of 300Bs over 2a3's? - Vinnie 05:06:37 08/18/01 (0)

I'm confuesed :( - Briner 01:07:09 08/18/01 (2)

Re: I'm confuesed :( - Jack G 05:36:32 08/18/01 (1)

Re: I'm confuesed :( - Briner 16:45:49 08/18/01 (0)

The glass ceiling and bass slam - Jack G 14:17:19 08/17/01 (3)

Re: The glass ceiling and bass slam - dave slagle 16:08:12 08/19/01 (0)

Buckinghams - mqracing 20:33:33 08/17/01 (1)

Altecs. (nt) - Jack G 05:25:16 08/18/01 (0)

45 over 2A3 or 300B, 300B over 2A3 - Gordon Rankin 12:48:01 08/17/01 (0)

You guys are making me sweat! - mwalsdor@cscc.edu 09:59:17 08/17/01 (0)

Re: How many of you prefer the sound of 300Bs over 2a3's? - car 09:41:43 08/17/01 (0)

Me - EdT 08:15:37 08/17/01 (0)

What?? - DrM 21:22:17 08/16/01 (13)

Re: What?? - Briner 23:43:34 08/16/01 (12)

Re: What?? - Paul Barker 01:02:46 08/17/01 (11)

Re: What about.... - steve jones 10:02:56 08/17/01 (4)

Re: What about.... - mqracing 08/17/0120:46:43 08/17/01 (1)

Re: What about.... - steve jones 09:05:09 08/18/01 (0)

YES - Paul Barker 10:47:27 08/17/01 (1)

Re: YES - steve jones 09:06:46 08/18/01 (0)

Re: What?? - SteveBrown 05:31:18 08/17/01 (2)

Re: What?? - JeffreyJ 10:17:20 08/17/01 (0)

Re: What?? - Paul Barker 07:55:10 08/17/01 (0)

Re: What?? - Preamp 02:26:45 08/17/01 (2)

Re: What?? - 7N7 04:35:16 08/17/01 (1)

Yes to all - DrM 07:16:14 08/17/01 (0)

Follow Ups

Re: What about.... - mqracing 08/17/0120:46:43 08/17/01 (1)

Re: What about.... - steve jones 09:05:09 08/18/01 (0)

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