John Curl's Blowtorch preamplifier part II

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It's a real problem even if you are careful. The galling is horrible. Great reminder.

I had to tighten a 3 inch dia threaded cap on an assembly to 12klbs normal force on 5 stacked bellvilles, and if there was no antiseize, it was essentially welded on. And even with pre-compression in 2000 lb increments.

I also locked up some T-nuts on a reflex cab when I forgot to lube the stainless capscrews.

jn
5 stack interesting could only find 3 on youtube http://www.youtube.com/watch?v=X-KChYBFiB0http://www.diyaudio.com/forums/www.youtube.com/watch?v=X-KChYBFiB0
 
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Mr John,

you might like my computer desk, btw.
$20k prototype of a table for medical surroundings, can lift 4400lb from 2' to 6' height, by hand or electrically, the 6' part of telescopic feet makes it difficult)

(5-head MD goes corporate enterprise club offered three times the normal manufacture cost, for them to be able to also charge three times as much leverage. so my old man told them to go screw themselves, literally. For a 2000 table contract at $2k each, in the late '70s, I'd likely been much more cooperative. :clown: )

Sentimental memorabilia with a 32'' x 60' Ikea solid beach top.

Why do you smoke?
 
Triodethom,
No problem, I do see that we do the most trade back and forth, it is just that I never see anything that says made in Canada on it. I know we do make cars there by the boatload but wonder what else besides forest products we are trading?

Yeah, cars, and forest products, and wheat, minerals (gold, nickel, uranium, aluminum, diamonds), beer, whisky, trains, aircraft, telecommunications equipment, oil, gas, electricity etc. Also Oracle, Bryston, Classe, Paradigm, Energy, PSB...
 
hmm, Kindhornman those .... dots ... what do they mean? the above list of pretty comprehensive, if those are out of sight, you must have a pretty prehistoric existence ;) I can understand nezbleu's frustration if this is a common event being forgotten about.

of course we know its not a deliberate omission on your part, but add a lot of that up and it would be pretty maddening
 
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Kindhornman, it probably comes as a surprise to most, but the largest exporter of oil to the United States isn't the Middle East, or Nigeria, or Venezuela, it is Canada. We use the money to pay for universal health care and subsidize otherwise unsustainable northern communities.
All we want with whatever money we have after being taxed into a lower middle class exsistance is your vintage JBL studio monitors, Blowtorchs, old tube Marantz, early Levinson, 70's Threshold, and Wilson speakers, that the Asian market doesn't take...

That will last until America get fracking well developed and makes it's own environmental mess and leaves us to play in the oil sands by ourselves...........

Where is John, waiting for us to talk about audio again so how do we get that pot boiling?. I run an all jfet /fet Borbely system all direct coupled - each stage DC servoed. The power amp has DC offset shudown detection and the input stage uses cascoded 2SK389/ 2SJ109. It''s all run faultlessly for 5 years, though I'm thinking of adding the dc offset detecton and mute to the preamp output to avoid an offset fault destroying the unreplaceable poweramp input jfets. Spectral did this DC monitoring in it's early preamps, does anyone else?
 
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it's own environmental mess

Sorry to dissapoint you, but the world's largest liquid sulphur and sulphuric acid trading company used to be owned 100% by a private equity club, consisting of retired Canadians. And all they cared about was a minimum profit margin.
So when it failed the mark, the shares went to the Toronto stock market.

Chemtrade, main office in Zug, Switserland, for tax reasons.
They have a liquid sulphur storage terminal in R'dam, 5 minute drive from where I live. (you're welcome to ask me howcome I know all that stuff)
 

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to step up to space age materials

Why bother? Use materials you "feel" comfortable with, without rationalising much.

The long and winded road to "the path one takes" is very personnal
Some new findings (pardon the deviation)
Be happy: Your genes may thank you for it / UCLA Newsroom

Not much different in the end from what one can distill from reading Diogenes Laërtius work (as a bonus, demistifying the Homines Universales mythical -to us- figures, is very instructive)
https://en.wikisource.org/wiki/Lives_of_the_Eminent_Philosophers


George
 
understand Bessel functions

Here's a series development for zero order Bessel (excuse the double dutch)
Personally, I find Taylor series a major visualizing aid.

My audio room TV-chair had trouble turning, for some reason my old college math book was underneith, blocking accurate attenuation :xeye:
Figured I might as well turn it into some positive use, the book, not the chair.

(up to age 30, ultimate was the magic word. Followed later by kiss. Over the years, I've come to realise more and more that common sense and standard practice from experience gained over many decades, beats innovative itch most of the times.)
 

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It depends on your focus. Do you just want to get by? Or do you want to make something special? Of course, most really good fundamental ideas come before the age of 30. For me, this was the complementary differential, complementary jfet follower, JC-1 pre-preamp ckt, etc.
Later, there is REFINEMENT. You know, complementary differential jfet, complementary folded cascode, etc. in ones 30's. In your 40's, it is often, IMPLEMENTING your ideas and running a company.
In my 50's, I gave up everything except to fool around in the lab, to repair and upgrade my previous designs, and to be a consultant for other manufacturers.
Now, in my 70's, I just try to keep up with my former knowledge and accomplishments.

You too, will get old, sometime.
 
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