[sdiy] equations up

[Magnus Danielson]

From: "metasonix at earthlink.net" <metasonix at earthlink.net>
Subject: Re: [sdiy] equations up
Date: Mon, 16 Jun 2003 12:25:04 -0700

> > Can I assume that he can't use the 3/2 power law directly or? Then he surely
> > needs a fairly long Taylor expansion.
> 
> I'd rather not go into it. His name is Norman Koren, and he
> wrote 2 long articles about this in GLASS AUDIO about 7-8 years ago.
> Both articles attracted considerable ill-informed criticism,
> so he decided to keep his mouth shut henceforth....
> I think he was right, but what's the point?
> 
> Tube audio attracts a lot of unsophisticated guys who don't know ANYTHING
> about analog circuit design--they read the Radiotron Designer's Handbook
> and regard it as infallible holy scripture. This is why old copies of
> the RDH can sell for $250 nowadays.

It is sad and it is true...

I rarely meet any such guys which have basic facts straight, and this doesn't
help when you get into the nitty gritty. Where not talking about engineering,
where are talking about practicing pseudo-religion with all the mumbo-jumbo that
goes with it.

> You oughta see the incoherent letters that VTV gets.....

Do I dare?

> > model is always a simplification of the real world and the closer the model is
> > the harder it gets to use it. Thus, you always have to ask yourself just how
> > closely you depend on your models correctness for your analysis and simulation
> > to make accurate predictions.
>  >However, it still remains just a model and there is
>  >several things which is wrong with it. It's all analog anyway.
> 
> Precisely. SPICE models will rarely give you an idea of an amplifier's
> linearity below about 1% THD. And that's the area where good analog
> designers work.

My point is to some degree that you have the model that you deserve. If you want
a truely good model you have to work alot on it to make sure it maps. Question
is if you gain time that way.

> Don't say "it's all analog" in a room full of EEs under the age of 30!
> They might strangle you with a USB cable....

I know...

I am just above 30 (32 actually) and I've seen analog electronics in real life
and not briefly on a postcard or hear rumours about it in the university.
But I usually beat the youngsters to abeedance before they cougth breath before
reaching for their USB cable. I'm the kind of guy they ask in to "solve"
problems and "operate" the measurement instruments. Then there is this pool of
instruments that I am amongst the few to pull up to the bench (willingly).

People doesn't even know what ECL actually is... and PECL is just plain
mysterious!

Cheers,
Magnus