[Bret Ludwig[_2_]]

On Mon, 30 May 2011 02:23:45 -0700 (PDT), Patrick Turner

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wrote:
On May 28, 7:59 pm, flipper wrote:
On Thu, 26 May 2011 16:32:44 -0700 (PDT), Patrick Turner

wrote:
On May 26, 7:35 pm, flipper wrote:
On Thu, 26 May 2011 00:37:17 -0700 (PDT), Patrick Turner

wrote:
I mentioned......
I have never seen any commercial design with PFB and NFB -

Of course you have and I gave you examples the last time you said the
same thing.

I've been saying the same thing because I've never seen PFB used in
commercial amps like the way its done in RDH4 at that amp.

Now you've changed it again by adding "like the way."

Sometimes
bootstrapping is PFB, but usually the gain increase is mild, from gain
with a load to gain which approaches µ. However, come to think about
it, Dynaco bootstrapped the pentode input tube anode RL ahead of the
triode concertina to boost the gain of the pentode.

Told ya so.

The Harmon Kardon 'Trio' also uses PFB and is the basic topology I've
used in at least three of mine.

The gain with
bootstrapping a pentode often rises much more than with a triode tube
because the pentode has its anode feedback screened off from the
electron stream. Pentode µ is gm x Ra, and as pentode Ra is so high
then µ is high.

BTW,
I have to repair the design results of acountants and bean counters
all too often.

You've never had to do it even once because bean counters don't do
design. Never have, don't now, and never will.

IMHO,

Your 'opinion', and following gibberish, is twaddle. It may fool
fellow ignorants who, like you, haven't a clue but it's drivel to
those of us who've worked with your so called 'bean counters' and done
professional product design.

I don't speak from 'opinion' and cartoons. I speak from fact, having
been there and done that.

Its OK, every man's facts are another man's fictions, and one man's
trash is another man's treasure.

More gibberish. Go bang your head on a wall and see how far you get
wishing it were 'fiction' rather than solid fact.

I just see lots of what I don't want to buy or approve of or want to
be involved in and if everyone was like me the world would collapse.
But fear not and be grateful for the human diversity around you now.

It should be blindingly obvious by now that you are not representative
of the market.

Of course, it's also blindingly obvious that accountants are trained
in accounting, which is pretty much why they're called accountants,
and not design but, then, it being obvious to everyone else has never
stopped your delusions yet.



It's true that more robust construction would have made these things
last longer, but to be fair, no one realistically figured anyone would
be running these things fifty or sixty years hence.


Saul Marantz (yes, I know) was determined to make the finest quality
hi-fi equipment and spared little in the quest to do so. His build
cost was double and then some of what his nearest competitor,
McIntosh, spent per unit.

Avery Fisher (yes, he was too) was more mainstream but still put a
lot of build cost in his product as compared to his competitors.

Both businesses are out of business in terms of being an American
manufacturer. McIntosh is also owned by Japanese, BUT are allowed to
operate autonomously and they are still manufacturing in Binghamton.

We can look at the classic Mac products and say there were several
aspects where they could have done better but the salient fact is,,
they are still here.

Quad never set out to be the technical ulimate but to be a usable
integrated system and they succeeded marvelously.

Even the Dynaco ST70, which I have slammed long and hard, has to be
admitted as having been insanely successful in its day. By the
standards of its day it was a great product because a college kid
could afford a Dyna pre and ST70, and AR table and an AR acoustic
suspension speaker set in 1963. Some portable record player outfits
cost nearly as much. Again, no one realistically thought thay would be
running in 2011.

Had the dyna been "built right" it would have had to cost more, maybe
considerably more. One area where they shaved was weight to meat a
Railway Express shipping target. That's why the power transformer is
undersize. The profit margins in this stuff were minimal.

It's like a car. Yeah, if ALL the Ford Mustangs had had 9 inch rears,
five bolt disc brake setups and so forth they'd have been better cars,
but 90% of them were going to the crusher in five or six years anyway.
If they had overbuilt them it would have made little difference in
this rate. A great many cars get driven to the crusher under their own
power.