[Trevor]

"Scott Dorsey" wrote in message
...
Er wasn't it YOU (or was it Arny?) who stated "with exploded electrolytics
the second" (most common cause of equipment failure) ?
That is NOT just because of reverse polarity. It's because of POOR quality
electro's being SO common now.

NOBODY said that.

Right, YOU cut out the direct quote and claim nobody said it! :-)

Lets add it back again shall we.

----------
" Honestly, this is the most common failure mode for consumer products
receiving the wrong polarity, with exploded electrolytics the second"
----------


I said that, of the failures due to reverse polarity, most of them were
failures of protection diodes or of capacitors.

Nope, see actual quote above. I simply explained most exploded electro's
these days are NOT due to reverse polarity.


Stop putting words in my mouth. Go back and read what I posted.

Done AND reposted above, after you felt the need to snip it BEFORE claiming
I am putting words in your mouth.
The trouble with trying to rewrite history on usenet is that you cannot
delete al copies.


I think this entire thread is the result of your misreading what other
people
are saying.

Now that we can agree on at least.

Trevor.

[Trevor]

"Trevor" wrote in message
u...
I think this entire thread is the result of your misreading what other
people are saying.

Now that we can agree on at least.

****, I should have been clear here too that I mean *YOUR* (and others)
misreading of what *I* wrote originally.

Trevor.

[Scott Dorsey]

Trevor wrote:
"Scott Dorsey" wrote in message
Right, YOU cut out the direct quote and claim nobody said it! :-)

Lets add it back again shall we.

----------
" Honestly, this is the most common failure mode for consumer products
receiving the wrong polarity, with exploded electrolytics the second"
----------

How do you parse that?

For consumer products receiving the wrong polarity
-- the most common failure mode is protection diode failure
-- the second most common is exploded electrolytics.

I don't understand WHERE you get any mention of exploded electrolytics
here in any context OTHER than in consumer electronics receiving the
wrong polarity.

I said that, of the failures due to reverse polarity, most of them were
failures of protection diodes or of capacitors.

Nope, see actual quote above. I simply explained most exploded electro's
these days are NOT due to reverse polarity.

Read that quote a few times until you understand what I said. It may help
to draw a sentence diagram.

Stop putting words in my mouth. Go back and read what I posted.

Done AND reposted above, after you felt the need to snip it BEFORE claiming
I am putting words in your mouth.

You have a severe reading comprehension problem here. Read that sentence
again.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Trevor]

"Scott Dorsey" wrote in message
...
Trevor wrote:
"Scott Dorsey" wrote in message
Right, YOU cut out the direct quote and claim nobody said it! :-)

Lets add it back again shall we.

----------
" Honestly, this is the most common failure mode for consumer products
receiving the wrong polarity, with exploded electrolytics the second"
----------

How do you parse that?

For consumer products receiving the wrong polarity
-- the most common failure mode is protection diode failure
-- the second most common is exploded electrolytics.


IF that is now your claim, then in my opinion you are WRONG.
If it is allowed to stand as written, then exploded electro's are indeed
right up there, and probably number one cause of consumer electronics
failure at the current time.


I don't understand WHERE you get any mention of exploded electrolytics
here in any context OTHER than in consumer electronics receiving the
wrong polarity.

Because THAT is exactly the main cause of electro failure as I said, NOT
just incorrect polarity. Lets be real here, MOST devices that suffer from
electro failure are mains powered from an internal supply, and cannot
possibly fail due to the consumer connecting polarity wrong.
Your continued claims to the contrary simply make you look stupid.


I said that, of the failures due to reverse polarity, most of them were
failures of protection diodes or of capacitors.

Nope, see actual quote above. I simply explained most exploded electro's
these days are NOT due to reverse polarity.

Read that quote a few times until you understand what I said. It may help
to draw a sentence diagram.

YOU may have thought you were restricting your statement as you now claim
(but for what reason God only knows) However you sure didn't WRITE it.


Stop putting words in my mouth. Go back and read what I posted.

Done AND reposted above, after you felt the need to snip it BEFORE
claiming
I am putting words in your mouth.

You have a severe reading comprehension problem here. Read that sentence
again.

Sure I can GUESS what you mean, however that does NOT make what I simply
added incorrect. If YOU think it does then YOU have the reading
comprehension problem.
In fact now placing such a limitation on your statement makes YOU incorrect,
since the biggest cause of failure in consumer electronics at the current
time in mine AND many others experience, is poor quality electro's which
have been correctly used as designed, and failed anyway!

And WHY the hell do you feel the need to go on and on about it? You'd save
more face by simply dropping the issue IMO. You sure aren't making yourself
look any smarter to the rest of the world!


Trevor.

[Scott Dorsey]

Trevor wrote:
"Scott Dorsey" wrote in message
...
Trevor wrote:
"Scott Dorsey" wrote in message
Right, YOU cut out the direct quote and claim nobody said it! :-)

Lets add it back again shall we.

----------
" Honestly, this is the most common failure mode for consumer products
receiving the wrong polarity, with exploded electrolytics the second"
----------

How do you parse that?

For consumer products receiving the wrong polarity
-- the most common failure mode is protection diode failure
-- the second most common is exploded electrolytics.


IF that is now your claim, then in my opinion you are WRONG.
If it is allowed to stand as written, then exploded electro's are indeed
right up there, and probably number one cause of consumer electronics
failure at the current time.

That's true but it has NOTHING to do with what I am saying. Read the
sentence again until you understand it.

I don't understand WHERE you get any mention of exploded electrolytics
here in any context OTHER than in consumer electronics receiving the
wrong polarity.

Because THAT is exactly the main cause of electro failure as I said, NOT
just incorrect polarity. Lets be real here, MOST devices that suffer from
electro failure are mains powered from an internal supply, and cannot
possibly fail due to the consumer connecting polarity wrong.
Your continued claims to the contrary simply make you look stupid.

You are using an invalid argument called "asserting the contrapositive"
here. Please go back and read the sentence until you understand it.

I _only_ referred to the failures caused by reversed polarity. All
other failures are NOT the subject of the sentence and whether they
are not common has NOTHING to do with anything I said.

YOU may have thought you were restricting your statement as you now claim
(but for what reason God only knows) However you sure didn't WRITE it.

Go back and read the sentence again.

And WHY the hell do you feel the need to go on and on about it? You'd save
more face by simply dropping the issue IMO. You sure aren't making yourself
look any smarter to the rest of the world!

Because I do not like having words put in my mouth by someone who has
incorrectly interpreted my statements and then goes on to claim to the
entire world that I said something else.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Trevor]

"Scott Dorsey" wrote in message
...
IF that is now your claim, then in my opinion you are WRONG.
If it is allowed to stand as written, then exploded electro's are indeed
right up there, and probably number one cause of consumer electronics
failure at the current time.

That's true but it has NOTHING to do with what I am saying. Read the
sentence again until you understand it.

It has everything to do with what *I* said. Read what *I* said again until
YOU understand it.


You are using an invalid argument called "asserting the contrapositive"
here. Please go back and read the sentence until you understand it.

You are using an invalid argument called "arguing from the general to the
particular" Please go back and read what *I* wrote until you understand it!

I _only_ referred to the failures caused by reversed polarity. All
other failures are NOT the subject of the sentence and whether they
are not common has NOTHING to do with anything I said.

Yes it does. Your claim is blatantly wrong IF only electro failures due to
reverse polarity are considered.


Go back and read the sentence again.

You really are a stupid boring old fart that thinks putting others down
somehow boosts his stupid arguments. it doesn't.


And WHY the hell do you feel the need to go on and on about it? You'd save
more face by simply dropping the issue IMO. You sure aren't making
yourself
look any smarter to the rest of the world!

Because I do not like having words put in my mouth by someone who has
incorrectly interpreted my statements and then goes on to claim to the
entire world that I said something else.

Nope, I simply added to your claim the REAL reason for most electro failure.
YOUR continued argument to the contrary is what is making you look a
complete moron to the rest of the world. You certainly don't need any help
from me!


Trevor.

[timewarp2008]

"Sam Trenholme" wrote in message
...
In article ,
timewarp2008 wrote:

your double-blind mumbo jumbo.

With add due respect, I smell a troll. Or, more accurately, a crackpot.
To wit:

* This guy is using an anonymous account. Yeah, this is allowed in
Usenet, but is not common; most other posters here (including myself)
post with our real names.

Maybe you've never had the pleasure of a troll going real-world on
you, harrassing your clients and threatening your family. Good for
you.

Or is his contributions to
r.a.p consist of flaming anyone to a crisp who tells him that "if you
can't hear the difference in a double blind test, then the difference
can't be heard".

You already demonstrrated (and even admitted) that you didn't really
read that thread very carefully, and you were very politely chided for
it already, but once again, you show that you weren't paying
attention. I said nothing even resembling your misrepresentation.
Graham, the proudly cluless lackwit, went on for scores, even hundreds
of posts, waxing clueless on his "belief" that anything that can't be
heard in a double-blind test is absolutely bull****, and couldn't
possibly be a valid reason for selecting a microphone. He riffed on
this, ad nauseam. Actual professionals in the field mentioned such
factors as off-axis performance, reliability, known preferred
coloration, and a host of other reasons, even the simple business
reason that it can be profitable to meet a client's specifications if
they're willing to pay enough money. All of this went in one of
Graham's ears and out his nether orifice, while he insulted everyone
who disagreed with him (which included many of the best-informed
sources on the net), and he pontificated on the universal
applicability of double-blind, and the universal imagined bull****tery
of any and all other considerations, all based on his non-technical
fact-free "beliefs." He seems to thing that the value of cash in hand
is just a "placebo."

So now, he's advocated that someone else modify his equipment by
replacing a single diode with a full-wave bridge, for a host of
reasons which all fail the faith-based universal standard that he's
still spewing on that other thread. I pointed out that simple fact of
hypocrisy, and you jump to some conclusion that's reminiscent of some
of the strawmen that he has dreamt up.

I'm very familiar with double-blind comparisons, both what they're
good for, and what they're useless for. For more than a year, a while
back, the focus of my work was designing and carrying out double-blind
comparisons of various audio equipment, including designing a suite of
software to facilitate the gathering and analysis of subjective
assessment from dozens of listeners in such tests. I have a very good
idea what can and cannot be heard in a double-blind test. And, unlike
the comedy character that Billy plays on that other thread, I'm
familiar with a whole host of reasons for microphone selection that
can't be evaluated with double-blind testing. I'm a firm believer in
the known laws of physics and acoustics, and I've also run up against
the limits of oversimplified models to have a very good idea where
those limits lie. And I know who pays the bills. If you want to tilt
at imagined audiophool windmills, you're not going to get much action
by accusing me of saying things I never said. Audio religious
proseletyzers don't get much traction here; fortunately, they don't
seem to like the getting-hit-on-the-head lessons.

What you do with your killfilters is up to you, of course, but it
would be a lot more productive to killfile Bill Graham, who seems to
have no other life than to post thousands upon thousand of words of
utter bull**** trolling on a single thread, before I've even finished
making a single post. You say you've been around Usenet before; maybe
it was so long ago that you forgot the instructions to newbies that
you might want to read an entire thread before stepping in it. I do a
lot more reading here than posting, and if my occasional hobby of
calling trolls out for their trollery really bothers you, then
killfile away! I know that there are some who don't like me, but I do
have a pretty deep and broad history of experience in audio and music,
pro and otherwise. And I really don't give a flying fourier how he
hacks up his own cheezy M.I. equipment; if anyone needs idiot-proof
equipment it's him.

.... so meet Numpty Graham, the r.a.p. village idiot, whom you're
implicitly and perhaps unwittingly defending. I hope you enjoy his
kookdancing. Why don't you ask around about what people think of him?
You might find the answers more entertaining than the ones you'll get
about me.

[timewarp2008]

On Jan 10, 8:17*pm, (Scott Dorsey) wrote:
Because I do not like having words put in my mouth by someone who has
incorrectly interpreted my statements and then goes on to claim to the
entire world that I said something else.
--scott

Yeah, there's an awful lot of that sort of thing going around lately!

[Scott Dorsey]

Trevor wrote:

I _only_ referred to the failures caused by reversed polarity. All
other failures are NOT the subject of the sentence and whether they
are not common has NOTHING to do with anything I said.

Yes it does. Your claim is blatantly wrong IF only electro failures due to
reverse polarity are considered.

My sentence specifically is talking about reverse polarity, since the
thread is about reverse polarity. And since the sentence begins
specifically referring to the case of reverse polarity. So, you would
think that I am talking only about reverse polarity, yes. Go back again
and read what I said.

Nope, I simply added to your claim the REAL reason for most electro failure.

Yes, but this has absolutely nothing to do with the thread, which is about
reverse polarity. Go back again and read what I said.

YOUR continued argument to the contrary is what is making you look a
complete moron to the rest of the world. You certainly don't need any help
from me!

I have never at any point argued the contrary, I only have argued that
these failures are irrelevant when the subject is reverse polarity. Go
back again and read what I said. You are putting words in my mouth again.
--scott



Trevor.




--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Bill Graham]

Scott Dorsey wrote:
In article ,
Sam Trenholme wrote:
I noted that you advised someone else to invest time and effort in
modifying a piece of his sound equipment, not yours, with
absolutely no evidence that you or anyone else would detect an
improvement in a double-blind test.

His suggestion is a modification to the power supply part of the
circuit. Not the audio part. His suggestion would make the device
in question more reliable; it's not to change its sound.

In the case of a gain pedal where it may be one transistor, some
resistors and a coupling capacitor, it's hard to break apart the
power supply part and the audio part. Most of these things have no
regulation, no constant current sources, and some of them even rely
on transistor leakage for bias which is a no-no everywhere else in
the world.

You could argue this is an incompetent design, but then again if
people like the way it sounds, who cares?
--scott

For sure, these pedals are not, "professional equipment". I don't think I
would attempt to modify a very expensive piece of professional equipment. If
it costs in the thousand dollar and up range, I will send it back to the
manufacturer to be repaired, if for no other reason than to avoid destroying
my warrantee. But a guitar pedal? Give me a break. Even if I destroy it, I
could justify it on the basis of a learning experience.

[Sam Trenholme]

* This guy is using an anonymous account. Yeah, this is allowed in
Usenet, but is not common; most other posters here (including myself)
post with our real names.

Maybe you've never had the pleasure of a troll going real-world on
you, harassing your clients and threatening your family. Good for
you.

No, I haven't had that, but I once had a troll attempt to contact my
employer to complain about me pointing out the guy was a pathological
liar. There's a reason I keep my current employment secret, and why my
mailing address is a PO box (actually, a "Mail Boxes etc." mailbox).

Yes, there are reasons to be anonymous, but it also means people will
more likely think you're trolling.

Graham, the proudly clueless lack-wit,

It doesn't impress me that you're so bitter against this person. As I
just posted in another thread, it would be better to killfile him and go
on with your life.

anything that can't be heard in a double-blind test is absolutely
bull****

The thing is this: I put people who think double-blind is somehow
invalid in the same category as people who deny the moon landing. It's
not science, and it's self-dishonesty.

he insulted everyone who disagreed with him

If I see him do that, I will consider killfiling him.

what can and cannot be heard in a double-blind test
^^^^^^

(Google readers: I'm underlining the word "cannot")

Sorry, but I'm going to have to side with Bill here.

If it can not be heard in a double-blind test, it can not be heard. The
only exception I would make to that is the supposed "Hypersonic Effect"
that Oohashi keeps talking about in his papers, but, quite frankly, I'm
not going to believe it until someone besides Oohashi can reproduce the
results in a peer-reviewed paper.

There are a lot of makers of audio gear who make a good deal of money
having people doubt the validity of double-blind studies. Look at the
fan base for Super Audio CD, even though Meyer and Moran conclusively
showed that no one can hear the difference between a redbook CD and a
Super Audio CD (given good 16/44.1 converters) under normal
circumstances (Other studies have similar findings).

When the Meyer/Moran study came out, the lunatic fringe at sa-cd.net
went bonkers. They insulted Meyer and Moran every way they could,
trying desperately to put holes in the study. One common rant was "you
can't trust double-blind studies!".

I know who pays the bills.

Exactly. There's, again, a lot of money to be made with people who
don't believe in double-blind studies. But, I find it very dishonest to
let money get in the way of facts.

Audio religious proselytizers don't get much traction here;
fortunately, they don't seem to like the getting-hit-on-the-head
lessons.

My experience over the years is that this place is more friendly to
people who reject double-blind studies than, say, hydrogenaudio.org
(I've been posting here on and off since 1993).

What you do with your killfilters is up to you

If it makes you feel any better, I've decided to not killfile you right
now. You seem interested enough in discourse; real trolls move on to
the next person to harass once they get killfiled by someone and could
care less whose killfile they are in.

you forgot the instructions to newbies that you might want to read an
entire thread before stepping in it.

Well, this thread has been around for about a month and my upstream's
retention is not that long. And, yes, I did look back in the thread as
far as I could. Then again, since I do run my own local Usenet feed
(leafnode is your friend), I will be able to retain threads for as long
as it fits in my partition for Usenet (over 3 gigs for a couple dozen of
newsgroups).

- Sam

--
#Sam Trenholme http://samiam.org -- Usenet user since September 1993#
######## My email address is at http://samiam.org/mailme.php ########
# The following script works around an annoyance in the Nano Editor #
cat | awk '{a=a $0 "\n";if($0 ~ /[a-zA-Z0-9]/){printf("%s",a);a=""}}'

[Gareth Magennis]

I did a quick test today on a couple of old wall warts I had lying around.
A 9v 500mA unregulated wall wart produced 3A through a 1N4007. A 9v
unregulated 1000mA wall wart produced 5 amps. I would guess 12v or 15v wall
warts would fare a lot better.

No fuses or wall warts were harmed in this brief experiment.


Gareth.

[Kevin Aylward[_4_]]

"timewarp2008" wrote in message
...


I'm very familiar with double-blind comparisons, both what they're
good for, and what they're useless for.

Such as?

Sure, if people like the look of something, irrespective of what it sounds
like, than that may be a basis for buying something. One local Blondie
tribute band around my way, has a decent mic cartridge in a standard
telephone handle, used for the start of "Hanging on the telephone". Looks
quite cool.

However, if the point is decide whether something is worth buying solely on
its technical merits, a double-blind test will tell you all you need to
know.

Kevin Aylward B.Sc.

www.kevinaylward.co.uk
"Live Long And Prosper \V/"

[Kevin Aylward[_4_]]

"Sam Trenholme" wrote in message ...


anything that can't be heard in a double-blind test is absolutely
bull****

The thing is this: I put people who think double-blind is somehow
invalid in the same category as people who deny the moon landing. It's
not science, and it's self-dishonesty.

I agree.

I have an overall axiom that I use. Its the "No magic" axiom

http://www.kevinaylward.co.uk/replicators/magic.html

The world is pretty much how one actually sees it. There are no, gods,
pieces, pink unicorns, tea pots orbiting mars etc.

Kevin Aylward B.Sc.

www.kevinaylward.co.uk
"Live Long And Prosper \V/"

[RD Jones]

On Jan 11, 11:43*am, "Gareth Magennis"
wrote:
I did a quick test today on a couple of old wall warts I had lying around..
A 9v 500mA unregulated wall wart produced 3A through a 1N4007. *A 9v
unregulated 1000mA wall wart produced 5 amps. *I would guess 12v or 15v wall
warts would fare a lot better.

No fuses or wall warts were harmed in this brief experiment. *

Gareth.

Yes, but was the diode harmed ?

rd

[Gareth Magennis]

"RD Jones" wrote in message
...
On Jan 11, 11:43 am, "Gareth Magennis"
wrote:
I did a quick test today on a couple of old wall warts I had lying
around.
A 9v 500mA unregulated wall wart produced 3A through a 1N4007. A 9v
unregulated 1000mA wall wart produced 5 amps. I would guess 12v or 15v
wall
warts would fare a lot better.

No fuses or wall warts were harmed in this brief experiment.

Gareth.

Yes, but was the diode harmed ?

rd


No, as the experiment was brief. I didn't want to destroy 2 potentially
useful wall warts to see which would melt first.

If anyone has enough time they could surely experiment with passing various
currents through the protection diodes typically found in guitar pedals, and
determine what currents and for for how long produce what results.
(They're cheap as chips - much cheaper than a fuse).

Me, I can't be arsed,


Gareth.

[Trevor]

"Gareth Magennis" wrote in message
...
No, as the experiment was brief. I didn't want to destroy 2 potentially
useful wall warts to see which would melt first.

Unlike the designers, you didn't think it was a good idea to find out with
your equipment right? :-)


If anyone has enough time they could surely experiment with passing
various currents through the protection diodes typically found in guitar
pedals, and determine what currents and for for how long produce what
results. (They're cheap as chips - much cheaper than a fuse).

Only if the fuse is a glass type.

Trevor.

[Gareth Magennis]

"Trevor" wrote in message
u...

"Gareth Magennis" wrote in message
...
No, as the experiment was brief. I didn't want to destroy 2 potentially
useful wall warts to see which would melt first.

Unlike the designers, you didn't think it was a good idea to find out with
your equipment right? :-)


If anyone has enough time they could surely experiment with passing
various currents through the protection diodes typically found in guitar
pedals, and determine what currents and for for how long produce what
results. (They're cheap as chips - much cheaper than a fuse).

Only if the fuse is a glass type.

Trevor.




Trevor, I'm sure most here have noticed by now your consistent and incessant
disingenuous posts.

You are, I believe, fundamentally dishonest, and I have no intention of
arguing with you.

[Bill Graham]

Sam Trenholme wrote:
* This guy is using an anonymous account. Yeah, this is allowed in
Usenet, but is not common; most other posters here (including
myself) post with our real names.

Maybe you've never had the pleasure of a troll going real-world on
you, harassing your clients and threatening your family. Good for
you.

No, I haven't had that, but I once had a troll attempt to contact my
employer to complain about me pointing out the guy was a pathological
liar. There's a reason I keep my current employment secret, and why
my mailing address is a PO box (actually, a "Mail Boxes etc."
mailbox).

Yes, there are reasons to be anonymous, but it also means people will
more likely think you're trolling.

Graham, the proudly clueless lack-wit,

It doesn't impress me that you're so bitter against this person. As I
just posted in another thread, it would be better to killfile him and
go on with your life.

anything that can't be heard in a double-blind test is absolutely
bull****

The thing is this: I put people who think double-blind is somehow
invalid in the same category as people who deny the moon landing.
It's not science, and it's self-dishonesty.

he insulted everyone who disagreed with him

If I see him do that, I will consider killfiling him.

what can and cannot be heard in a double-blind test
^^^^^^

(Google readers: I'm underlining the word "cannot")

Sorry, but I'm going to have to side with Bill here.

If it can not be heard in a double-blind test, it can not be heard.
The only exception I would make to that is the supposed "Hypersonic
Effect" that Oohashi keeps talking about in his papers, but, quite
frankly, I'm not going to believe it until someone besides Oohashi
can reproduce the results in a peer-reviewed paper.

There are a lot of makers of audio gear who make a good deal of money
having people doubt the validity of double-blind studies. Look at the
fan base for Super Audio CD, even though Meyer and Moran conclusively
showed that no one can hear the difference between a redbook CD and a
Super Audio CD (given good 16/44.1 converters) under normal
circumstances (Other studies have similar findings).

When the Meyer/Moran study came out, the lunatic fringe at sa-cd.net
went bonkers. They insulted Meyer and Moran every way they could,
trying desperately to put holes in the study. One common rant was
"you can't trust double-blind studies!".

I know who pays the bills.

Exactly. There's, again, a lot of money to be made with people who
don't believe in double-blind studies. But, I find it very dishonest
to let money get in the way of facts.

Audio religious proselytizers don't get much traction here;
fortunately, they don't seem to like the getting-hit-on-the-head
lessons.

My experience over the years is that this place is more friendly to
people who reject double-blind studies than, say, hydrogenaudio.org
(I've been posting here on and off since 1993).

What you do with your killfilters is up to you

If it makes you feel any better, I've decided to not killfile you
right now. You seem interested enough in discourse; real trolls move
on to the next person to harass once they get killfiled by someone
and could care less whose killfile they are in.

you forgot the instructions to newbies that you might want to read an
entire thread before stepping in it.

Well, this thread has been around for about a month and my upstream's
retention is not that long. And, yes, I did look back in the thread
as far as I could. Then again, since I do run my own local Usenet
feed (leafnode is your friend), I will be able to retain threads for
as long as it fits in my partition for Usenet (over 3 gigs for a
couple dozen of newsgroups).

- Sam

And, I have yet to insult anyone on this, or any other forum. If you read
the threads carefully, I think you'll find all the insults have been
directed at me by others.

[Bill Graham]

Gareth Magennis wrote:
I did a quick test today on a couple of old wall warts I had lying
around. A 9v 500mA unregulated wall wart produced 3A through a
1N4007. A 9v unregulated 1000mA wall wart produced 5 amps. I would
guess 12v or 15v wall warts would fare a lot better.

No fuses or wall warts were harmed in this brief experiment.


But was it a "quick double blind test"? :^)

[timewarp2008]

On Jan 11, 12:25*pm, Sam Trenholme
wrote:

There's, again, a lot of money to be made with people who
don't believe in double-blind studies. *But, I find it very dishonest to
let money get in the way of facts.

Audio religious proselytizers don't get much traction here;
fortunately, they don't seem to like the getting-hit-on-the-head
lessons.

Double-blind tests can be useful for comparing components that can be
quickly swapped in and out of an audio system without changing the
rest of the system. They produce subjective judgements about the
comparison of the components, and being double-blind, they can
eliminate judgments based on knowledge outside the realm of
audibility. But being comparison tests, they don't tell you about a
single component, which is often what is really needed. And they don't
produce hard objective facts such as can be had with careful
measurements, with calibrated test equipment, in a controlled
environment. I can measure the radiation pattern of a speaker system,
and get data from which I can produce both a series of polar plots for
every third-octave in the audio band, and a series of frequency
response plots for every five degrees in full horizontal and vertical
circles. I can learn significant things about speakers from this kind
of data. Measurements can yield a wealth of accurate understanding of
how a device responds, in ways that just aren't available in double-
blind tests. If you want simple repeatable and verifiable data about a
single component, not subjective opinions about comparisons, then
double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are invalid, as well as the other extreme
belief that they are all-knowing and all-seeing, are two faith-based
extremes, and the fact-based reality is not found at either of those
extremes. If you think that you can know all the audio and technical
characteristics about a piece of audio equipment from double-blind
listening comparisons, then you're talking religion, not science,
technology, or professional audio.Double-blind tests can be useful for
comparing components that can be quickly swapped in and out of an
audio system without changing the rest of the system. They produce
subjective judgements about the comparison of the components, and
being double-blind, they can eliminate judgments based on knowledge
outside the realm of audibility. But being comparison tests, they
don't tell you about a single component, which is often what is really
needed. And they don't produce hard objective facts such as can be had
with careful measurements, with calibrated test equipment, in a
controlled environment. I can measure the radiation pattern of a
speaker system, and get data from which I can produce both a series of
polar plots for every third-octave in the audio band, and a series of
frequency response plots for every five degrees in full horizontal and
vertical circles. I can learn significant things about speakers from
this kind of data. Measurements can yield a wealth of accurate
understanding of how a device responds, in ways that just aren't
available in double-blind tests. If you want simple repeatable and
verifiable data about a single component, not subjective opinions
about comparisons, then double-blind listening tests are not useful.

You can prove that audiomystics can't hear the difference between
ordinary large-gauge twisted-pair speaker cables and dilithium triple-
lutz wire with ibex hide insulation. You can show that suspending
gopher-wood icosahedrons and crysatl hockey pucks above your listening
position doesn't make the sound any less "veiled." Double-blind
comparisons, especially ABX tests, are great for identifying cases
where differences are not really perceptible. But in the real world of
professional sound reinforcement and recording, double-blind tests
have limited usefulness. Sometimes I bring more microphones than I
need to record a performance, and record extra tracks; and compare
them after the fact to decide which ones I like for the final product.
Double-blind comparisons can be useful in this type of decision
making. But I don't think double-blind tests are of much use when
configuring an array of speaker boxes for an outdoor festival stage,
although variations in the configuration of such arrays can have
clearly audible differences. Double-blind tests areng going to tell me
what kind of power a device requires, what kind of connectors I need,
what signal levels it can't handle, et pro-audio cetera.

Double-blind tests just aren't such a big deal in pro audio, for very
good reasons. One of the most important reasons is that they don't
give you repeatable objective data, which many professionals can
interpret accurately, quickly, and lucratively. The audiophool belief
that double-blind tests are completely invalid, as well as the other
extreme belief that double-blind tests are all-knowing and all-seeing,
are two faith-based extremes, and the fact-based reality is not found
at either of those extremes. If you think that you can know all the
audio and technical characteristics about a piece of audio equipment
from double-blind listening comparisons, then you're talking religion,
not science, technology, or professional audio.

[timewarp2008]

On Jan 11, 7:15*pm, "Numpty Graham" wrote:
And, I have yet to insult anyone on this, or any other forum. If you read
the threads carefully, I think you'll find all the insults have been
directed at me by others.-

If you read the threads carefully, you can see how far up his asshole
Numpty's head must be to tell such a whopper!

[timewarp2008]

On Jan 12, 4:41*pm, timewarp2008 wrote:
sneck

Oops. Mea culpa. Sorry about the egregious multi-paste. My CTRL-V must
have gotten stuck, and I was at fault for not taking care to read what
I had pasted and posted.

[Trevor]

"Gareth Magennis" wrote in message
...
If anyone has enough time they could surely experiment with passing
various currents through the protection diodes typically found in guitar
pedals, and determine what currents and for for how long produce what
results. (They're cheap as chips - much cheaper than a fuse).

Only if the fuse is a glass type.

Trevor, I'm sure most here have noticed by now your consistent and
incessant disingenuous posts.

You are, I believe, fundamentally dishonest, and I have no intention of
arguing with you.

Good! I'm sure intelligent people don't claim a piece of fuse wire is
necessarily more expensive than a diode, and pretend anyone who thinks
otherwise is "fundamentaly dishonest". But you are welcome to your
delusions, I have no intention of arguing with morons any more either!
That's what kill files were invented for. I will not feel at all upset if
you choose to use it, as I will!

Trevor.

[Kevin Aylward[_4_]]

"timewarp2008" wrote in message
...

On Jan 11, 12:25 pm, Sam Trenholme
wrote:

There's, again, a lot of money to be made with people who
don't believe in double-blind studies. But, I find it very dishonest to
let money get in the way of facts.

Audio religious proselytizers don't get much traction here;
fortunately, they don't seem to like the getting-hit-on-the-head
lessons.

And they don't
produce hard objective facts such as can be had with careful
measurements, with calibrated test equipment, in a controlled
environment. I can measure the radiation pattern of a speaker system,
and get data from which I can produce both a series of polar plots for
every third-octave in the audio band, and a series of frequency
response plots for every five degrees in full horizontal and vertical
circles. I can learn significant things about speakers from this kind

of data. Measurements can yield a wealth of accurate understanding of
how a device responds, in ways that just aren't available in double-
blind tests. If you want simple repeatable and verifiable data about a
single component, not subjective opinions about comparisons, then
double-blind listening tests are not useful.

I pretty much agree with all of this, and the bits sniped for brevity. I
would say that this is discussing a different aspect of the debate that was
really not being addressed in this context. Yes, double blind tests, by its
nature can only address subjective issues. A double blind test does not use
measuring equipment, so by construction, is not addressing detailed
objective issues.

I will say that if I am designing a general power amplifier, I see
absolutely no reason whatsoever to ever listen to it until it is quite
finished and ready for sale. The technical specifications is quite
sufficient. It is relatively straightforward to design an amplifier that is
a "straight piece of wire with gain".


Kevin Aylward B.Sc.
www.kevinaylward.co.uk

[Trevor]

"Kevin Aylward" wrote in message
...
I will say that if I am designing a general power amplifier, I see
absolutely no reason whatsoever to ever listen to it until it is quite
finished and ready for sale. The technical specifications is quite
sufficient. It is relatively straightforward to design an amplifier that
is a "straight piece of wire with gain".

Of course, unfortunately the subjectivists will argue forever about how
different types of wire affect the sound, whether with or without gain, and
straight or not! :-)

Trevor.

[William Sommerwerck]

It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

[Arny Krueger]

"William Sommerwerck" wrote in
message
It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

The usual answer is gain, input impedance, noise, nonlinear distortion at
all relevant frequencies, linear distortion, including for power amps: Their
performance into low impedance, nonlinear, and reactive loads. On the AC
supply side, power factor.

[William Sommerwerck]

"Arny Krueger" wrote in message
...
"William Sommerwerck" wrote in
message

It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

The usual answer is gain, input impedance, noise, nonlinear
distortion at all relevant frequencies, linear distortion, including
for power amps: Their performance into low impedance, nonlinear,
and reactive loads. On the AC supply side, power factor.

We've argued this before, and those criteria are certainly pertinent. No one
would design an amplifier without considering all of them. (Gerry Stanley
famously said that the reason the DC-300A sounded better than the DC-300 was
that he hadn't paid attention to the earlier amplifier's behavior with
reactive loads.)

I ask the following, hoping you will carefully consider it before
responding... How do you know that reducing harmonic and IM distortion to
extremely low levels with test signals necessarily produces a comparable
reduction in such distortions with program material? In a broader sense, how
do you know that an amplifier's behavior with a complex signal (ie, music)
is accurately predicted by its behavior with simple signals?

To the best of my knowledge, only QUAD and Crown have investigated this
question. An ex-Crown employee told me they could get a 90dB (!!!) null
between input and output on the Power Line amplifiers (which are no longer
made) with program material. One might reasonably assume that such an
amplifier would not subjectively alter the sound in any way.

Of course, Gerry Stanley also designed the K-series switching amps (also no
longer made) which are the worst-sounding amps I've ever heard, so bad you
don't even need to compare them with anything else to hear their
wretchedness. Yet they measure extremely well on lab tests.

I've owned amps designed by Dan D'Agostino and John Curl, which measure
beautifully, but sound quite different. There's no question that there's
something measurably different about them -- but no one wants to put out the
effort to find out what it is.

[Arny Krueger]

"William Sommerwerck" wrote in
message
"Arny Krueger" wrote in message
...
"William Sommerwerck" wrote
in
message

It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

The usual answer is gain, input impedance, noise,
nonlinear distortion at all relevant frequencies, linear
distortion, including for power amps: Their performance
into low impedance, nonlinear, and reactive loads. On
the AC supply side, power factor.

We've argued this before, and those criteria are
certainly pertinent. No one would design an amplifier
without considering all of them. (Gerry Stanley famously
said that the reason the DC-300A sounded better than the
DC-300 was that he hadn't paid attention to the earlier
amplifier's behavior with reactive loads.)

That is a well-known story. The modest SOA performance of the DC 300 was the
result of the relatively poor SOA performance of the output devices at hand.
At the point of design, nobody knew for sure what the customer operational
environment actually was. The first time they stuck their toes into the
water they found out! Ouch!!!

Hence my comments about : "Their performance
into low impedance, nonlinear, and reactive loads."


I ask the following, hoping you will carefully consider
it before responding... How do you know that reducing
harmonic and IM distortion to extremely low levels with
test signals necessarily produces a comparable reduction
in such distortions with program material?

Hmm, I did my first amplifer bench measurements when I was 13. That was over
50 years, and a lot of time spent on the bench and in relevant university
classes ago.

Both the theory and the practice say that if you do everything right it
works.

In a broader
sense, how do you know that an amplifier's behavior with
a complex signal (ie, music) is accurately predicted by
its behavior with simple signals?

Oh, that is simple. You test the amplifier with complex signals. There are
ways to test equipment for both nonlinear and linear distoriton using
regular music as your test signals.

Also, if 1 or 2 sine wave(s) is the classic simple test signal, then a
test signal composed of 30+ of them should be at least a little more
complex, right? The results of tests with 1-2 sine waves, 30+ sine waves,
and actual real world music converge very nicely, thank you!

To the best of my knowledge, only QUAD and Crown have
investigated this question.

Speaks to your lack of knowlege and memory.

An ex-Crown employee told me
they could get a 90dB (!!!) null between input and output
on the Power Line amplifiers (which are no longer made)
with program material.

That would be consistent with my own bench observations. However, I
distrust nulling approaches like that for reasons I've gone over many times
on public forums including probably this one.

One might reasonably assume that
such an amplifier would not subjectively alter the sound
in any way.

I don't think I've done any DBTs on those exact amplifiers, but I have
tested equipment that measured worse, and its output was indistinguishable
from its input, when the two were level matched.

Of course, Gerry Stanley also designed the K-series
switching amps (also no longer made) which are the
worst-sounding amps I've ever heard, so bad you don't
even need to compare them with anything else to hear
their wretchedness. Yet they measure extremely well on
lab tests.

Ditto above.

I've owned amps designed by Dan D'Agostino and John Curl,
which measure beautifully, but sound quite different.

Given your well-known lack of expertise and patience to what is considered
to be a proper listening test in the circles I travel, any of your comments
about ampliier sound are taken with a huge shaker of salt.

There's no question that there's something measurably
different about them -- but no one wants to put out the
effort to find out what it is.

We've never been able to fix your head. ;-)

[geoff]

Kevin Aylward wrote:

I pretty much agree with all of this, and the bits sniped for
brevity. I would say that this is discussing a different aspect of
the debate that was really not being addressed in this context. Yes,
double blind tests, by its nature can only address subjective issues.
A double blind test does not use measuring equipment, so by
construction, is not addressing detailed objective issues.

Those 'subjective issues' may in fact be objective issues relating to
aspects not covered by your beloved specs.

geoff

[Scott Dorsey]

In article ,
William Sommerwerck wrote:
It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

I don't know about his, but one of mine is that it should not catch fire
when driving a 2uF capacitive load like a Quad ESL....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[William Sommerwerck]

It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

I don't know about his, but one of mine is that it should
not catch fire when driving a 2uF capacitive load like a
Quad ESL...

Have you experienced this? grin

[Scott Dorsey]

geoff wrote:
Kevin Aylward wrote:

I pretty much agree with all of this, and the bits sniped for
brevity. I would say that this is discussing a different aspect of
the debate that was really not being addressed in this context. Yes,
double blind tests, by its nature can only address subjective issues.
A double blind test does not use measuring equipment, so by
construction, is not addressing detailed objective issues.

Those 'subjective issues' may in fact be objective issues relating to
aspects not covered by your beloved specs.

In the case of things like pedals and mixing consoles where 90% of the
system is the user interface, the subjective issues are often the most
important part of the system evaluation.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

William Sommerwerck wrote:
It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

I don't know about his, but one of mine is that it should
not catch fire when driving a 2uF capacitive load like a
Quad ESL...

Have you experienced this? grin

With several different amps, some of them with good reputations from
seemingly-reputable companies. You'd think people would keep track of
where their poles and zeros were going, but no.

Although the absolute best amplifier failure I have ever seen was when
I was recording some band at the Little Five Points Pub in Atlanta
and the Phase Linear in the house sound system started spitting sparks
four or five feet into the air, accompanied by very loud hum.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Doug McDonald[_4_]]

On 1/18/2011 6:47 AM, Arny Krueger wrote:


An ex-Crown employee told me
they could get a 90dB (!!!) null between input and output
on the Power Line amplifiers (which are no longer made)
with program material.

That would be consistent with my own bench observations. However, I
distrust nulling approaches like that for reasons I've gone over many times
on public forums including probably this one.



I'd be interested in hearing ... again ... why you think that. We assume
a real speaker load on the power amp, in the same room (thus, microphonics
are included in the test.)

Doug McDonald

[PStamler]

On Jan 18, 4:47*pm, Doug McDonald
wrote:
On 1/18/2011 6:47 AM, Arny Krueger wrote:



An ex-Crown employee told me
they could get a 90dB (!!!) null between input and output
on the Power Line amplifiers (which are no longer made)
with program material.

That would be consistent with my own bench observations. However, I
distrust nulling approaches like that for reasons I've gone over many times
on public forums including probably this one.

I'd be interested in hearing ... again ... why you think that. We assume
a real speaker load on the power amp, in the same room (thus, microphonics
are included in the test.)

I'm not Arny, but will jump in anyway.

The problem with nulling tests is that they privilege one type of
performance over another. Unless the amplifier has very wide
bandwiidth, phase shifts at the top and the bottom will show up as
sizeable error. In a straight-wire nulling test, a wideband amplifier
with high distortion will typically null better than a narrower-band
amplifier with very low distortion.

I'm not going to get into the question of whether phase shifts at
frequency extremes are audible. What I'm saying, rather, is that
straight-wire null tests privilege phase shifts above all other errors
to such a great extent that they are effectively useless.

Peter Walker proposed "crooked-wire" bypass and null tests, in which
the alternative path had the same phase-shift characteristics as the
amplifier. It turned out to be very difficult to implement; the
compensation network for one amplifier had about 16 components, and
the null went away whenever the amp's temperature changed, as it
invariably did when the amp played.

In short, null tests are too sensitive to one parameter of dubious
audibility, to the extent that other parameters are swamped.

Peace,
Paul

[Arny Krueger]

"Doug McDonald"
wrote in message
On 1/18/2011 6:47 AM, Arny Krueger wrote:


An ex-Crown employee told me
they could get a 90dB (!!!) null between input and
output on the Power Line amplifiers (which are no
longer made) with program material.

That would be consistent with my own bench observations.
However, I distrust nulling approaches like that for
reasons I've gone over many times on public forums
including probably this one.

I'd be interested in hearing ... again

Paul Stamler's explanation does it right.

I can only add a practical example.

Let's say that a power amp's gain through the nulling circuit is 0.1 dB
different from ideal. It also has 1% THD. The output of the nulling device
is the same for either cause. Yet, a 0.1 dB level mismatch is always trivial
in the real world, while 1% THD can be a serious problem.

... why you think that.

Real world experience in many different contexts. Study of the relevant
technical literature as it was published over a period of 50 or more years.

We assume a real speaker load on the power amp, in
the same room (thus, microphonics are included in the
test.)

The problem is not that nulling is insensitive. The problem is that nulling
conflates a wide variety of problems that have vastly different degrees of
audiblity.

[Scott Dorsey]

PStamler wrote:

I'm not going to get into the question of whether phase shifts at
frequency extremes are audible. What I'm saying, rather, is that
straight-wire null tests privilege phase shifts above all other errors
to such a great extent that they are effectively useless.

I wouldn't say they are useless, I would just say that it's necessary
to actually analyze the difference component and see where it's coming
from before just concluding that there is a problem due to the mere
intensity average of the difference component.

They are still useful tests but they are not tests that can be used
without further analysis.

In short, null tests are too sensitive to one parameter of dubious
audibility, to the extent that other parameters are swamped.

This is true, but it's a thing that can be compensated for in many
cases.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Kevin Aylward[_4_]]

"William Sommerwerck" wrote in message
...

"Arny Krueger" wrote in message
...
"William Sommerwerck" wrote in
message

It is relatively straightforward to design an amplifier
that is a "straight piece of wire with gain".

Perhaps it is. What are your design criteria?

The usual answer is gain, input impedance, noise, nonlinear
distortion at all relevant frequencies, linear distortion, including
for power amps: Their performance into low impedance, nonlinear,
and reactive loads. On the AC supply side, power factor.

We've argued this before, and those criteria are certainly pertinent. No
one
would design an amplifier without considering all of them. (Gerry Stanley
famously said that the reason the DC-300A sounded better than the DC-300
was
that he hadn't paid attention to the earlier amplifier's behavior with
reactive loads.)

I ask the following, hoping you will carefully consider it before
responding... How do you know that reducing harmonic and IM distortion to
extremely low levels with test signals necessarily produces a comparable
reduction in such distortions with program material?

Its called the laws of physics.

In a broader sense, how
do you know that an amplifier's behavior with a complex signal (ie, music)
is accurately predicted by its behavior with simple signals?

Its called the laws of physics. There is nothing special about music
signals. Unfortunately, there are just too many unqualified individuals
around making all sorts of dubious claims that this is not so.

Sure, in principle one can consider some amps of 50 years ago, or tube amps
with ac coupling causing all sorts of dynamic biasing issues, or thermal
tail problems, but today, one would have to work pretty hard to get those
problems, well, not unless your design capabilities were somewhat less than
stellar.

If one takes a competentally designed DC coupled amplifier, and say, gets
0.01% IMD when driven with say, equal levels of steady state 19Khz and 20Khz
to just below clipping and at very small signals, its pretty much
inconceivable that the amp is not going to be a piece of wire with gain. In
principle, that one test is not measuring much, but in realty, it does.
Other aspects, all things being equal, go hand in hand.

The route of your question is, do the bias conditions of an amp change
significantly, when a signal is applied such that it makes the steady state
distortion tests invalid? Well, not if the amp is designed not to do that.

If an amplifier is linear, then a simple signal is all that is required to
predict the results for any signal. This is a provable mathematical fact. If
the amplifier is non-linear, than sure, more is required. However, if the
amplifier is "linear enough", than the simple tests are enough.



Kevin Aylward B.Sc.
www.kevinaylward.co.uk