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rsdio 23rd April 2011 09:35 AM

A Concise Guide to the Published Amplifier Circuits of Nelson Pass
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 23rd April 2011 09:39 AM

nice !


rsdio 23rd April 2011 09:41 AM

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 23rd April 2011 09:48 AM

useful link, if you want to have patents :

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

look here , too :

Zen Mod 23rd April 2011 09:59 AM

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

- 5710522 :

- 5376899 :

- 5343166 :

- 4899387 :

- 4107619 :

- 4752745 :

- 3995228 :

Zen Mod 23rd April 2011 10:11 AM


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 :rofl: )


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


rsdio 23rd April 2011 10:52 AM

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 23rd April 2011 11:02 AM

1 Attachment(s)

just don't take my words too seriously

I never do

Nelson Pass 23rd April 2011 07:28 PM

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


Gyuri 23rd April 2011 08:15 PM

Hi Nelson!
What is that S.?


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