New webpage on loudspeaker cables
 

On Fri, 14 Aug 2009 15:55:26 +0100, Eeyore
wrote:

You've never seen my work btw, so you're in no position to comment.

Well this will tell us how many commercial products you have sold
then. So much for your attempt at a ****ing match with Jim - I've seen
plenty of his.

d

New webpage on loudspeaker cables
 

David Looser wrote:

"Eeyore" wrote

The name Armstrong dates his knowledge massively.

The principles were exactly the same then as they are now. In addition the
stuff he has posted here shows that he has a level of understanding of those
principles that go well beyond yours.

Fundamental principles may not have changed but practice has.

Graham


--
due to the hugely increased level of spam please make the obvious adjustment to
my email address

New webpage on loudspeaker cables
 

"Eeyore" wrote in message
...


Fundamental principles may not have changed but practice has.

In what way?

Perhaps you'd like to explain exactly how the techniques you have used to
ensure unconditional stability are an improvement on those used by Jim in
his designs for Armstrong.

David.

New webpage on loudspeaker cables
 

David Looser wrote:

"Eeyore" wrote

Fundamental principles may not have changed but practice has.

In what way?

More competent application of the basic principles, aided by computer
modelling and reduction in the cost of devices so you can use more of them
without breaking the bank.


Perhaps you'd like to explain exactly how the techniques you have used to
ensure unconditional stability are an improvement on those used by Jim in
his designs for Armstrong.

(a) I don't have the time.

(b) It's commercially confidential.

(c) Some of them are obvious though like the typical LRC or LRRC network at
the output of the amp itself which effectively 'isolates it' from load
impedance ( including cable ) effects at high frequencies. These have been
used for decades. How you could make a stable amp without them or attempt to,
baffles me. It means that the amp 'sees' almost exactly 8 ohms resistive in
the MHz + region.

Graham


--
due to the hugely increased level of spam please make the obvious adjustment
to my email address

New webpage on loudspeaker cables
 

"Eeyore" wrote in message
...


David Looser wrote:

"Eeyore" wrote

Fundamental principles may not have changed but practice has.

In what way?

More competent application of the basic principles,

Competence isn't a matter time. So apparently you are claiming that you are
more competent than Jim. I have to say, reading your posts, that I doubt
that to be true.

of aided by computer
modelling and reduction in the cost of devices so you can use more of them
without breaking the bank.

Neither of which has anything to do with having a thorough understanding of
the issues.


Perhaps you'd like to explain exactly how the techniques you have used to
ensure unconditional stability are an improvement on those used by Jim in
his designs for Armstrong.

(a) I don't have the time.

(b) It's commercially confidential.

Yeah, yeah. Excuses excuses.


David.

New webpage on loudspeaker cables
 

Dave Plowman wrote:

The effect of pure shorts and opens is an ASININE
concept, completely
out of touch with the real world.

Nothing wrong in covering everything on such an article.

Everything? So plots for intermediate values can be inferred
by interpolation?

As certain
speakers may well *tend* towards a short or OC at certain
frequencies.

Pure wriggling. Surely they did maths at your school?
Underlining "tend" doesn't make it any more true. No speaker
tends towards either a short or OC within its frequency
range. They may go down, but they come back up. They
may go up, but they come back down. On the way, they may
tend toward several maxima and minima. They never tend
towards, approach, or approximate to, either zero or
infinity. But never mind, it really doesn't matter in this
context. Should you ever design a speaker, it may be worth
keeping in mind that power transfer can be awkward to
achieve into either a short or an OC.

It would be an entirely different matter if this research
was being used
to sell or promote some product.

Research? Don't be daft. He's connected a machine to some
cables and blindly reported the ensuing data, with
supporting handwaving and gibberish.

The whole article's a sales gimmick, but this time HFN's
been rumbled. The only hi-fi news these days is weirdo news,
but unfortunately there are other comics much better at
weirdo than HFN.

Ian

New webpage on loudspeaker cables
 

In article ,
Ian Iveson wrote:
Pure wriggling. Surely they did maths at your school?
Underlining "tend" doesn't make it any more true. No speaker
tends towards either a short or OC within its frequency
range. They may go down, but they come back up. They
may go up, but they come back down. On the way, they may
tend toward several maxima and minima. They never tend
towards, approach, or approximate to, either zero or
infinity.

And you have measured every one - and at all frequencies, even those
outside the audio range of the speaker? Amplifiers generally have a much
wider bandwidth that the speaker they're driving, so finding out the
effects of the cable on the amp seems to me no bad idea.

It would be an entirely different matter if this research was being
used to sell or promote some product.

Research? Don't be daft. He's connected a machine to some cables and
blindly reported the ensuing data, with supporting handwaving and
gibberish.

You've not actually read the article, then? And the others in the series?

The whole article's a sales gimmick, but this time HFN's been rumbled.

Really? And just what is it selling? Must be a very subtle message if it
is.

The only hi-fi news these days is weirdo news, but unfortunately there
are other comics much better at weirdo than HFN.


--
*Is it true that cannibals don't eat clowns because they taste funny?

Dave Plowman London SW
To e-mail, change noise into sound.

New webpage on loudspeaker cables
 

In article , David Looser
wrote:
"Eeyore" wrote in message
...

Perhaps you'd like to explain exactly how the techniques you have
used to ensure unconditional stability are an improvement on those
used by Jim in his designs for Armstrong.

(a) I don't have the time.

(b) It's commercially confidential.

Yeah, yeah. Excuses excuses.

Going off a tangent: I must admit I found (b) above quite interesting/
amusing. There does seem to have been a trend in recent decades for makers
and desigers to feel that physics and engineering can somehow be kept
'secret'.

A few decades ago makers of items like hifi amps and tuners where happy to
let users have circuit diagrams and explain to people how their equipment
worked. They were proud of what they had built, and wanted to explain its
ingenuity. Indeed, in my exprience they generally felt that open
discussions with other engineers about what they had done would help
everyone to improve. And they had the confidence that they would have new
ideas and improve as they learned.

More recently there has been a tendency to treat circuitry as being a
'commercial secret', perhaps even extending to behaviour like removing the
printing from some components so others can't read the part numbers. I even
read reports some time ago of a well-known designer putting ball bearings
into the potting of his output transfomers to stop anyone opening them up
to see what he had done.

Afraid that to me this behaviour seems to betray a lack of confidence in
their work, and in their ability to have newer or better ideas later on,
perhaps even almost paranoia in extreme cases. It seems odd to me as it
seems like a belief that others are frantic to 'steal' their 'idea',
rather than being quite capable of doing things for themself. Perhaps
in some cases a form of self-flattery to think others would need to
do so.

I have often wondered if this obsession with 'secrecy' over matters which
could usually be uncovered *if* some other skilled engineer with resources
*wanted* to reverse-engineer what had been done is a factor in the growth
of 'snake oil' as it feeds ignorance amongst users and may help
technobabble to flourish.

Perhaps this is a factor in the way users have been led to treat some
designers and makers as 'magicians' who practice a magic art beyond the
ability of mere mortals to understand.

When I worked in audio I and other designers at other companies quite
happily exchanged ideas, and loaned circuits to each other. I guess it may
be very different now. If so, it may well impede the education of some
designers as they will find help from their peers harder to obtain.


My personal view is that if you buy something, then it is yours, and
with that you should be entitled to have the info to allow you to
understand how it works or alter it if you so prefer. So in another
area my preference for Linux and the approach of its community to
software. And in electronics, a wish for full technical onfo on any
item I might want to buy/use. Perhaps this is the 'academic' in me
wanting to understand things. Maybe it is that I object to being
told, "we want your money, but you can only use the item, not be
allowed to try and understand how it works." I've had various items
of 'consumer equipment' which have broken and are then impractical
to repair as the makers won't release info or parts. So there may
also be what seems like a scam here to me, causing repairable or
improvable items to end up as landfill.

I wonder how many computers will end up as landfill as a result of
people feeling "Must have Windows 7 to follow everyone else"?...

....but that is well OT. :-)


So coming back on topic, the above does rather support my wondering if all
current/recent amplifiers are as good as they *could* be if their
designers/ makers were more open, and less fearful of others being able to
study what they had done.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

New webpage on loudspeaker cables
 

Phil Allison wrote:

"Eeyore = Graham Stevenson = a total **** "

Don't buy or use potentially unstable amplifiers.

** Potentially unstable is an epithet that applies to just about every
amplifier and every person ever made.

This was more of an issue about 30 years ago.

** Don't you just love pommy ****wits who never actually state what they are
falsely alluding to ??

Text book symptom of rampant, congenital autism.

Blah, blah, blah.

Amp design has advanced radically in the last 30 years.

Graham


--
due to the hugely increased level of spam please make the obvious adjustment to
my email address

New webpage on loudspeaker cables
 

On Tue, 18 Aug 2009 04:21:40 +0100, Eeyore
wrote:



Phil Allison wrote:

"Eeyore = Graham Stevenson = a total **** "

Don't buy or use potentially unstable amplifiers.

** Potentially unstable is an epithet that applies to just about every
amplifier and every person ever made.

This was more of an issue about 30 years ago.

** Don't you just love pommy ****wits who never actually state what they are
falsely alluding to ??

Text book symptom of rampant, congenital autism.

Blah, blah, blah.

Amp design has advanced radically in the last 30 years.


Really? I've seen a few schematics of recent designs, and they look
awfully familiar. I always see a balanced transconductance input
stage, followed by a voltage amplifier stabilized by Cdom, then a
power stage, all contained within a feedback loop. What do you believe
has changed, because I can't see it?

d