A Concise Guide to the Published Amplifier Circuits of Nelson Pass

[rsdio]

I have read all of the articles by Nelson Pass, and then went back and tried to take notes on what topics were discussed in each. Here in the Pass forum, a few folks (myself included) are new, and hoping to find a decent starting point. For my part, I have compiled an index of the articles that I think are necessary for understanding the Pass amplifiers, including Zen Variations and First Watt.

The linked file is a first draft. If anyone has suggestions, please let me know. As I learn more, I hope to flesh out the guide and then make a final version before too long. At the moment, 4 pages (with two focused on the juicy bits) seems like a good length. I've included some very basic comments about some of the technology, but perhaps I could revise this to be more of an introductory tutorial which points to Papa's more in-depth coverage.

A Concise Guide to the Published Amplifier Circuits of Nelson Pass

Brian Willoughby

 

[Zen Mod]

nice !

 

[rsdio]

I hope to weave in more ties between the patents and the articles. So far, I have the main two patents. If anyone can help suggest articles which exemplify other patents, please let me know.

Now that I mention it, I should include the patents as if they were articles, despite the tendency for them to be much harder to read than Papa's natural prose.

 

[Zen Mod]

useful link, if you want to have patents :

PAT2PDF - Free PDF copies of patents: Download and print!


look here , too :

http://www.google.com/patents?as_q=...inm_ap=0&as_miny_ap=&as_maxm_ap=0&as_maxy_ap=

 

[Zen Mod]

so - numbers are ( dunno are links for download just temporary ) :

- 5710522 : http://www.pat2pdf.org/patents/pat5710522.pdf

- 5376899 : http://www.pat2pdf.org/patents/pat5376899.pdf

- 5343166 : http://www.pat2pdf.org/patents/pat5343166.pdf

- 4899387 : http://www.pat2pdf.org/patents/pat4899387.pdf

- 4107619 : http://www.pat2pdf.org/patents/pat4107619.pdf

- 4752745 : http://www.pat2pdf.org/patents/pat4752745.pdf

- 3995228 : http://www.pat2pdf.org/patents/pat3995228.pdf

 

[Zen Mod]

btw.

dunno - either Papa is , in nature of his published circs , Zappawakoolike , or am I , in comprehensive ability , Zappawakoolike - but I can't see some special organization in his published circs ( go figure - it seems that SUSY patent goes before Aleph CCS patent ; if I remember correctly - he said somewhere that he patented SUSY , even if not fully digging it ; I'm not mocking here - he's the one who patented it , not silly Mighty ZM )



meaning - I think that you must stay at documentary level , without trying to add agenda spice

 

[rsdio]

I'm not sure that I follow you, but Papa does mention many times in the articles and Manuals that X and Aleph were out of order when comparing patents to products. Such is the nature of patents. They take anywhere from 9 to 18 months from filing to award. Also, some of Nelson's patents have never been used in a product, or the products were not very successful at all (not for lack of working, however).

One minor problem I had is whether to list patents by filing date or award date, but since I have focused on 'published' works, I think that the award date is the one. My next revision will have patents listing along with articles.

As for my idea of linking circuit designs to patents, I don't think that counts as "agenda spice." It should be fairly easy to see if a circuit is covered by a patent (well, maybe not so easy). At the very least, studying the Aleph active current source circuit well enough to recognize it in an article's circuit should be a good exercise, and the same goes for any of the other patents - it will just take time.

 

[Zen Mod]

naah

just don't take my words too seriously

I never do

 

[Nelson Pass]

That a very comprehensive overview. I'm flattered by the effort.

 

[Gyuri]

Hi Nelson!
What is that S.?

Wacky

 

[Zen Mod]

That a very comprehensive overview. I'm flattered by the effort.

naah

just don't tell that you don't feel worthy

 

[Nelson Pass]

No false modesty here....

 

[rsdio]

That a very comprehensive overview. I'm flattered by the effort.

All in a day's work (play?). Consider it my thanks for your inventions as well as your willingness to support understanding of audio circuitry through your articles.

 

[geraldfryjr]

Excellent! It sure helps too take the confusion out of all of the variations. jer

 

[qusp]

great job!! i imagine this will be a very commonly linked collection

 

[c12mech]

Very nice list. That will make it a lot easier for those of us that are new to the Pass amps in getting started.

 

[Bksabath]

Many tanks rsdio

Briliant

 

[pinkmouse]

So useful, it's now sticky.

 

[rsdio]

Thanks for all of the positive remarks, folks.

I have updated the document by 'splitting' the Power Supply section into unipolar and bipolar or split rails. The original list was a bit too long, and it seems that the distinction between types should improve the utility of the list. There are some other, minor revisions as well.

I hope I am not being impatient, since the weekend isn't even over, but I was hoping to get some constructive criticism. Does anyone have suggestions for improvements? I suppose I may need to wait a while before someone volunteers to match up some of the older patents with specific circuits from the articles.

 

[jan.didden]

One more:

http://www.linearaudio.net/userfiles/file/Volume_0_NP.pdf

jan didden