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Bromo <bromo@ix.netcom.com> wrote:
> On 4/24/04 2:31 PM, in article c6ebp5016pe@news4.newsguy.com,
> "outsor@city-net.com" <outsor@city-net.com> wrote:

> > I agree about current limits being the real physical reasons an amp
> > might sound different from another. But those advocating the inherent
> > amp sound different view say that when with equal current capacity,
> > amps will still sound different.

> Yes - this makes this sort f test rather useless in information or
> enlightenment.


As compared to, say, a typical high-end review of an amp?

> I do not see how this "challenge" serves anyone but the ego of the
> "debunker"...

Then, as many have already pointed out here, you don't understand
why the challenge was laid down in the first place. It is a response
to typical audiophile claims.


--

-S.

"They've got God on their side. All we've got is science and reason."
-- Dawn Hulsey, Talent Director

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Bromo wrote:
> On 4/24/04 10:15 AM, in article c6dsps02v1c@news3.newsguy.com, "chung"
> <chunglau@covad.net> wrote:
>
>>> Realisticqlly an amp running out of power is the main reason one would her
>>> distortion vs. another amp. Given the power requirements across the
>>> frequency band would reveal the differences in the amps -- the challenge is
>>> a false challenge, then!
>>
>> So you think any two amps with similar output power measurements would
>> sound the same? Works for me!
>
> Nope - you would have to measure distortion, intermod, channel separation,
> transient response, frequency response, and it is late I am sure I left
> something out....

So you just stated that there are differences that are in addition to
the drive capabilities of the amps. So just insuring that two amps have
similar drive capabilities does not insure that they sound the same.
Therefore you just prove that the challenge is not faulty at all!

>
>> On the other hand, the high-enders' position is that there is something
>> magical about the sound of expensive amps that cannot be quantized via
>> measurements. That's what the challenge attempts to debunk.
>
> I don't think it is a useful "challenge" - since you CANNOT divorce the
> needs of a particular speaker or transducer from this and still come up with
> anything useful to a consumer that I hope you are tring to "protect".

Note that they are not saying that they will match the noise,
distortion, interchannel effects, transient responses, etc. So if those
things would differentiate amps, then the challenge is meaningful.

>
> For instance Halcro advertises a THD that is much lower than most other
> amplifiers at a power level not likely to ever be reached. Perhaps that is
> their edge in this game of diminishing returns. The Theta Drednaught II
> shows a great amount of frequency extension - and given that I have designed
> (RF) amps for the last 10 years, I can see a small amount of value for that
> if it is true. It means the source of distortion has been moved to the
> component feeding the amp. Even if it is overkill, this is a HOBBY, where
> the pursuit of perfection is part of the fun (the most fun being music).

Question then is whether the Halcro can be differentiated from any other
amp with the same drive capabilities and similar frequency response. The
challenge can answer that.

>
>> So, in your opinion, why would anyone buy a $10K 100W amp, when there
>> are other 100W amps with low distortion available for $1K?
>
> I have no opinion - it depends upon the amp and the speaker. I have some
> Thield 2.4's and it required a fair amount of current to make the bass sound
> good. This made me seek out the best value to correct it given that I only
> had about 70-80Wpc. I ended up with a NAD S200 - which made the bass sound
> good without muddying the upper frequencies. I ended up paying more than
> $1k for it. (It was 225Wpc).
>
> If someone offers me a hand crafted piece of electronics, with a vanishingly
> low noise floor, low IMD and harmonics, incrementally better than your $1k
> amp, and wants to charge me $2-4k for it (more realistic) - I wouldn't fault
> him or her at all. Why should I?

But don't you want to know if another amp with the same output drive as
your NAD will sound the same? Maybe you don't, but the question is a
meaningful one, and I fail to see why you think you know the answer
before the test.

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On 4/25/04 10:14 AM, in article c6gh430a3h@news3.newsguy.com, "chung"
<chunglau@covad.net> wrote:

>>> So you think any two amps with similar output power measurements would
>>> sound the same? Works for me!
>>
>> Nope - you would have to measure distortion, intermod, channel separation,
>> transient response, frequency response, and it is late I am sure I left
>> something out....
>
> So you just stated that there are differences that are in addition to
> the drive capabilities of the amps. So just insuring that two amps have
> similar drive capabilities does not insure that they sound the same.
> Therefore you just prove that the challenge is not faulty at all!

The challenge is faulty for the following reasons:

1. You are stuck with that guys' speakers - bad sounding speakers will mask
an amps sound.
2. The person will equalize his amplifier - since his amplifier has sound
qualities he has to equalize to sound flat.

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From: chung chunglau@covad.net
>Date: 4/24/2004 10:28 PM Pacific Standard Time
>Message-id: <M%Hic.17630$YP5.1284125@attbi_s02>
>
>S888Wheel wrote:
>
>> From: chung chunglau@covad.net
>>>Date: 4/24/2004 7:15 AM Pacific Standard Time
>>>Message-id: <c6dsps02v1c@news3.newsguy.com>
>>>
>>
>>>
>>>On the other hand, the high-enders' position is that there is something
>>>magical about the sound of expensive amps that cannot be quantized via
>>>measurements. That's what the challenge attempts to debunk.
>>>
>>
>> Why do objectivists continue to burn this straw man? I don't know any
>> subjectivists who claim any "magic" is at work.
>>
>
>Oh yeah? A casual search finds the following post:
>
>
>http://groups.google.com/groups?q=tube+magic+group:rec.audio.high-end&hl=
en&lr=&ie=UTF-8&oe=UTF-8&group=rec.audio.high-end&selm=7mu81k%246gr%241%40
agate.berkeley.edu&rnum=3
>
>Here's what Zipser said in that post:
>
>"Probably the one and only solid state amplifier line that sonically
>posseses the same magic as your tube amplifier is the PASS Labs Aleph
>series of amplifiers."
>
>There are many references to "tube magic"; just do a google search on
>the various audio newsgroups.
>

Obviously figurative speech refering to a prefered sound from tubes. Hardly a
claim of the paranormal.

>BTW, you misunderstood what I said. I said that some high-enders believe
>there is something magical about the sound of certain highly touted
>amps.

Well please clarify what you are saying. Are you complaining about figurative
speech or are you complaining about claims of paranormal activity?

That does not mean that I am saying that subjectivists believe
>there is magic at work.

It did seem like you were.

It simply means that said high-enders cannot
>explain why these amps sound so great, since measurements do not explain
>such greatness.

So? Many people cannot explain many things they enjoy in life. That fact per se
does not mean they are making claims of paranormal experiences.

>
>It seems like you are imagining a strawman being burned. When someone
>says that something sounds magical, do you always assume that someone is
>saying there is magic at work?
>
>
>
>
>
>
>

It is not like such straw men have never been burned in the past by
objectvists. If you are complaining about hyperbole fine. It didn't look that
way to me. It looked like you were trying to tar and feather subjectivists as
believers in the paranormal. While I am sure many are, I am even more sure that
some are not. And the same is true for objectivists.

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Stewart Pinkerton <patent3@dircon.co.uk> wrote:
> On 24 Apr 2004 15:24:40 GMT, Thomas_Akerlund@hotmail.com (Thomas A)
> wrote:

> >However, if I would do the challenge, I would seek up two amps with
> >different HP filtering in the bass range (if such exist among car
> >amps; there is nothing in the rules what I can see about the built in
> >normal HP filtering of amps to avoid DC). Play the music to the film
> >"Fifth Element" and use speakers with e.g. 10 x 15 inch woofers in a
> >closed box system in a sealed small room. Play the song where there is
> >a sweep going down to 5 Hz at loud volumes and try to "feel" the
> >difference in the body. 1.5-3 dB difference in the 7-15 Hz region may
> >be percieved differently. Challenge rules, see
> >
> >http://groups.google.com/groups?q=%22richard+clark%22+challenge+rules+group:rec.audio.car&hl=en&lr=&ie=UTF-8&oe=ISO-8859-1&group=rec.audio.car&selm=3ff8669c.126950265%40news.east.cox.net&rnum=6

> Unfortunately, you failed to notice that in test condition no. 5,
> Richard is allowed to EQ the amps to have the same frequency response,
> negating this kind of cheap shot.

FWIW I found Clark's challenge and some of his replies to criticisms,
here

http://www.talkaudio.co.uk/vbb/sho [...] adid=18815

And alas it doesn't seem unusual for critics to have not actually
read the terms of the challenge (though that doesnt' stop them from
making erroneous claims about it!)

http://www.soundandvisionmag.com/i [...] A9838AAAE}

--

-S.

"They've got God on their side. All we've got is science and reason."
-- Dawn Hulsey, Talent Director

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On 24 Apr 2004 18:35:33 GMT, Bromo <bromo@ix.netcom.com> wrote:

>On 4/24/04 1:13 PM, in article cfxic.14174$0u6.2394685@attbi_s03, "Stewart
>Pinkerton" <patent3@dircon.co.uk> wrote:
>
>>>
>>> Given that the amplifiers' ability to drive difficult load is removed - then
>>> the challenge is removed quite effectively.
>>
>> Why? Where did you *ever* see a 'high end' maker claim that the
>> 'superior' sound of his amp had anything to do with sheer power?
>
>Power into low impedance and low to no global feedback is what I hear from
>most amplifier advertisements. Oh, that and a DC to daylight flatness with
>low distortion.

You will *never* see 'DC to blue light' and no global feedback
mentioned in connection with the same amplifier. You'll also not see
ability into low loads mentioned for anything but Krell and H-K. You
*will* see technobable like 'microdynamics' and 'soundstaging' bandied
about by ragazine reviewers - who will *never* submit to DBTs.

>> My Krell will drive a 1-ohm load continuously, but that has nothing to
>> do with how it *sounds* on normal speakers.
>
>The point is that how it can source a 1 ohm current load means you aren't
>restricted to 'normal' speakers (whatever those are) - and if there is a ton
>of current required - you have it without the amplifier going into some sort
>of foldback.

Which has what exactly to do with any notion of 'superior sound' into
normal speakers? You seem to have completely missed the claimed point
of 'high end' amplifiers. Please note that I agree with your point of
view, it's just that you seem to have stepped into a debate with no
actual conception of one side of it.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

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On 4/24/04 11:22 PM, in article c6fatj0rgk@news1.newsguy.com, "chung"
<chunglau@covad.net> wrote:

> Bromo wrote:
>> On 4/24/04 1:13 PM, in article cfxic.14174$0u6.2394685@attbi_s03, "Stewart
>> Pinkerton" <patent3@dircon.co.uk> wrote:
>>
>>>>
>>>> Given that the amplifiers' ability to drive difficult load is removed -
>>>> then
>>>> the challenge is removed quite effectively.
>>>
>>> Why? Where did you *ever* see a 'high end' maker claim that the
>>> 'superior' sound of his amp had anything to do with sheer power?
>>
>> Power into low impedance and low to no global feedback is what I hear from
>> most amplifier advertisements.
>
>
> OK, so there is another possible differentiator that would be tested for
> validity: low/no global feedback vs normal global feedback.
>
> Wouldn't it be nice if we can settle the issue of whether low/no global
> feedback sounds any different?

It won't be settled - you cannot prove a negative.

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On 4/24/04 11:25 PM, in article c6fb3j0rk4@news1.newsguy.com,
"outsor@city-net.com" <outsor@city-net.com> wrote:

> "So I tend to agree with another poster, the test is quite meaningless.
> If you want to buy an amp, you should not have to correct its
> frequency response due to its flaws. Better to buy an amp with no
> flaws."
>
> The ability to drive an extreme load at the edje of an amp's performance
> is not at issue. When an amp is driven into such a load and is overlaoded
> doesn't show a flaw, only that the load is outside it's performance design
> specs.

Actually testing to the extremes generally *are* int he design specs. Also,
the specifications are generally vague in many ways - aside from that a
lower impedance in the AB amplifier can generate greater distortion than at
a higher impedance.

An amp unable to properly drive a speaker is a VERY important measure of an
amp - especially if the amp and speaker are YOUR amps and speakers. If both
amps claim they can have enough current to power a Maggie 20.1 but one seems
to compress better on high peaks - well, which one is the "better" amp in
this case?

I recall reading a review in Absolute Sound where they compared a bunch of
amps ranging from $2k (Rotel) to about $6K - and their only comment was that
at normal listening levels, any of the amps would be easy to live with - and
the only differences were heard at a high level of drive.

>The real test is for those claiming "night and day" obvious anyone
> can hear them differences between amps with similar performance specs.

In the AS, they didn't make that claim in that one review if it makes you
feel any better.

The more I read and post in this thread, it seems to me that most of the
effort is trying to discredit a marketing department - and a few reviewers.

What benefit would I, as a consumer, would get from this effort? Especially
since it is designed not to help me find an amp that would match my speaker
well?

>If
> one looks enough some condition can be so extreme so as to drive one amp
> into an unstable condition, that in this instance is irrelevant.

This is ABSOLUTELY an important issue - unconditional stability is important
to understand before you plunk down any amount of money be it $10 or $10,000
for the amplifier.

In fact, this would be MORE IMPORTANT to point out about various amplifiers
than creating some sort of limited test to try to prove a negative.

> It is a
> purchase consideration when an amp of x cost and another of 10x are found
> by test to sound no different. The same consideration would apply under
> the extreme conditions you propose, why buy the second amp if the first
> costs 1/10 the other and sounds the same under those conditions.

But how relevant are those conditions to the people this demonstration is
trying to educate?

A really thorough ring out of both amplifiers with measurements followed by
a series of sound tests (blind tests) with speakers of various loads and
timbers plus stress testing to prove stability, protection and so on, would
be much more useful as far as education.

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On Sun, 25 Apr 2004 05:10:54 GMT, Bromo <bromo@ix.netcom.com> wrote:

>On 4/24/04 1:03 PM, in article P5xic.20708$aQ6.1263449@attbi_s51, "Nousaine"
><nousaine@aol.com> wrote:
>
>>> Given that the amplifiers' ability to drive difficult load is removed - then
>>> the challenge is removed quite effectively.
>>
>> Sure and how many "tough" loads are there? Stewart's speakers may qualify but
>> of the hunreds of home speakers I've tested I can't recall a single one
>> (including the 'stats) that would qualify as a difficult load to drive.
>
>Martin Logan has a 1 Ohm impedance at the high end.

Where there is virtually no power to be delivered to the speakers.
I've not found M-Ls to be particularly amplifier fussy.

>Apogees have a sub 1 Ohm impedance as well.

Only one model - the old Scintilla. All others have a mostly resistive
3-4 ohms impedance, but they do like lots of power as they're not very
sensitive.

>Thiels are notorious for requiring a lo of current in the bass (and tend to
>be 3 Ohms)

Indeed yes, but they're quite sensitive in the main, so a good
60-watter will generally do - and that's about the easiest size of amp
to design.

>Magnepans are -- magnepans and then to have a sub 5 Ohm load.

Any half-decent amp should drive a 4-5 ohm load without problems, it
then just becomes a matter of how loud you want to play.

>All of these are considered to be "difficult" to drive - and many integrated
>amp manufactuers place warnings on their amps to not have speakes with
>impedances that low!

I have not seen *any* respectable integrated amp (I'm not talking
about cheap receivers or surround-sound amps) which warns against 4
ohm loads. The decent ones such as Arcam are perfectly capable of
driving 2-ohm loads.

> Many times in loud passages the amps could overheat
>and trip thei protection circuit - or in extreme cases with no protections,
>blow up!

You must have different experience to mine regarding what any
reasonable person would call 'hi-fi' equipment.

>But, if you don't see it - feel free to take the "40Wpc into 8 Ohms at 1Khz"
>integrated and try to drive a Thiel 7.2....

No reasonable person would try such a thing. What is your point?

>> It is true that many autosound enthusiasts like to wire multiple woofers, often
>> with multiple coils, in ways that might qualify. But Richard Clark's challenge
>> has put the amp sound for autosound to rest as well.
>
>He is trying to prove a negative, so the quest will be forever.
>
>This whole thing struck a nerve - people doing a flashy sort of thing by
>putting up a large sum of money with rules constructed so they won't ever be
>"wrong"

Tell that to the 'high enders' who claim that say a Pass Labs Aleph
1.2 at £12,000 will sound 'obviously, night and day' different from a
$500 Yamaha AX-592. They have similar power capability, but claims
made for 'sound quality' are very different!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

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S888Wheel wrote:

>
>>BTW, you misunderstood what I said. I said that some high-enders believe
>>there is something magical about the sound of certain highly touted
>>amps.
>
> Well please clarify what you are saying. Are you complaining about figurative
> speech or are you complaining about claims of paranormal activity?
>
>

It really speaks volumes about how you are preconditioned to read
certain posts from the non-subjectivist side. I was not complaining
about anything at all, and yet you took it that I was.

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On 4/25/04 1:38 PM, in article 7ISic.32063$w96.2204064@attbi_s54, "Stewart
Pinkerton" <patent3@dircon.co.uk> wrote:

>> But, if you don't see it - feel free to take the "40Wpc into 8 Ohms at 1Khz"
>> integrated and try to drive a Thiel 7.2....
>
> No reasonable person would try such a thing. What is your point?

The point I was making is that the "challenge" when hyped (a $10k "prize is
hype in this case) might make an average consumer think that any old amp
low, mid or hi-fi was capable of driving any old speaker because "they sound
the same."

I have an AVR200 that used to drive my Thiel 2.4's - I now use a NADS200 to
do the same - the articulation and bass response improved noticably due to
the power - and according to the data sheet I had up to 90W available to do
that (1kHz at 4Ohms was supposed to be 140W). The extra current really
helped the sound I figure when driving that speaker. Made a difference,
when I expected very little.

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Bromo <bromo@ix.netcom.com> wrote:

> It won't be settled - you cannot prove a negative.

In an absolute sense, of course. But, in a probabilistic perspective,
one can sensibly conclude that something is very unlikely.

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Bromo wrote:

> On 4/24/04 11:22 PM, in article c6fatj0rgk@news1.newsguy.com, "chung"
> <chunglau@covad.net> wrote:
>
>> Bromo wrote:
>>> On 4/24/04 1:13 PM, in article cfxic.14174$0u6.2394685@attbi_s03, "Stewart
>>> Pinkerton" <patent3@dircon.co.uk> wrote:
>>>
>>>>>
>>>>> Given that the amplifiers' ability to drive difficult load is removed -
>>>>> then
>>>>> the challenge is removed quite effectively.
>>>>
>>>> Why? Where did you *ever* see a 'high end' maker claim that the
>>>> 'superior' sound of his amp had anything to do with sheer power?
>>>
>>> Power into low impedance and low to no global feedback is what I hear from
>>> most amplifier advertisements.
>>
>>
>> OK, so there is another possible differentiator that would be tested for
>> validity: low/no global feedback vs normal global feedback.
>>
>> Wouldn't it be nice if we can settle the issue of whether low/no global
>> feedback sounds any different?
>
> It won't be settled - you cannot prove a negative.
>

So your real concern with any test is that it does not prove the
negative? How about if you are the testee, and you cannot tell the
difference. Is that good enough for *you*?

While it may not constitute proof to you, to the rest of us if there is
no audible difference between 2 amps with vastly different amounts of
global feedback, then it certainly greatly reduces the significance of
the low/no global feedback claims.

As an engineer, aren't you curious to find out how the amount of overall
feedback affects the sound?

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On 25 Apr 2004 14:15:44 GMT, Bromo <bromo@ix.netcom.com> wrote:

>The time and effort might be spent a bit more productively - perhaps trying
>to research and measure all sources of sonic imperfections not already known
>- pushing the forefront of hearing sciences, and so on.

Actually, since we can already prove that dozens of amplifiers sound
exactly the same below the clipping point, the time and effort would
most definitely be better spent in selecting better speakers, and
placing them in the best position in a well-sorted room.

Of course, this would destroy 90% of 'high end' mythology - but
perhaps the world would be a better place for that............

--

Stewart Pinkerton | Music is Art - Audio is Engineering

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On 4/25/04 4:38 PM, in article c6h7k002j9q@news4.newsguy.com,
"jjnunes@sonic.net" <jjnunes@sonic.net> wrote:

> Bromo <bromo@ix.netcom.com> wrote:
>
>> It won't be settled - you cannot prove a negative.
>
> In an absolute sense, of course. But, in a probabilistic perspective,
> one can sensibly conclude that something is very unlikely.

Sure - one has to build confidence in this case. Though, with the
restrictions in place, it is difficult to build a simple enough case with so
many "if's and's and but's"

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On 4/25/04 7:20 PM, in article jJXic.34947$aQ6.1879434@attbi_s51, "Stewart
Pinkerton" <patent3@dircon.co.uk> wrote:

> On 25 Apr 2004 14:15:44 GMT, Bromo <bromo@ix.netcom.com> wrote:
>
>> The time and effort might be spent a bit more productively - perhaps trying
>> to research and measure all sources of sonic imperfections not already known
>> - pushing the forefront of hearing sciences, and so on.
>
> Actually, since we can already prove that dozens of amplifiers sound
> exactly the same below the clipping point, the time and effort would
> most definitely be better spent in selecting better speakers, and
> placing them in the best position in a well-sorted room.

I agree that is a good use of an end user's time and money - but still - if
people claim to hear a difference, it might be good to do the due diligence
as a scientific sort to see if there is anything to these claims. Some have
been made in the past that haven't helped, but some has been made that did.

> Of course, this would destroy 90% of 'high end' mythology - but
> perhaps the world would be a better place for that............

Mythology is bad - but I would be careful to discard the grain of truth with
it. Even if the golden eared claimants were incorrect for the reasons
*they* said - there might be something there important for sound
reproduction that they didn't realize.

Archived from groups: rec.audio.high-end (More info?)

"It won't be settled - you cannot prove a negative."

It has been suggested we don't prove anything, we fail to disprove. If we
propose that amps of similar electrical specs will sound different and a
listening test shows difference at a level of guessing, we haven't proven
some other amp pair willn't pass the test, we have however shown that it
fails to disprove the proposition that two such amps will sound alike. Do
enough of these examples of failing to disprove and the
confidence/potential that any future pars will sound different becomes so
small that we have little interest/motivation to continue trying to
disprove the proposition. That is the course that concensus building and
the way scientific "truth" is formed. That is the power of the current
benchmark in test results, we are now a good distance down the road that
so many attempts have failed to disprove that we are quickly losing
interest seeking those exceptions to the benchmark.

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"The contest is a silly endevour because of the various loads an amplifier
is
asked to drive into - each speaker is different in impedance and the
amount
of current required in order to get a nice, flat response out of it (or a
response the listener finds to his or her liking)."

Irrelevant and silly on it's face, if we are going to evoke the "silly"
metric into the discussion. In the test situation the speaker is an
independent variable, as is the nature of tests where one tries to hold
equal all but those things being tested. Even with the above truisms, the
yamaha sounded no different then the pass labs. As I recall in the clark
rules, any speaker was an option, any speaker and he still has his 10 k.
On the silly scale your series of red herrings about forcing amps into
current overload falls exactly where? The test is not to verfy the truism
that amps can be driven into overload and will sound different when doing
so. It is however the claim from the high end folk that the mega buck
pass lab and the old few hundred yamaha will sound different because the
former is high end and has inherent qualities, with other things being
equal, there will be a
"night and day" obvious sound easy as pie to identify.

Archived from groups: rec.audio.high-end (More info?)

"The more I read and post in this thread, it seems to me that most of the
effort is trying to discredit a marketing department - and a few
reviewers.

What benefit would I, as a consumer, would get from this effort?
Especially
since it is designed not to help me find an amp that would match my
speaker"

You have got it. The test was designed to do exactly the above. It was
to show that one can save money and stress knowing that a 1 k amp will
sound no different then the 10 k amp found in the hi fi rags and floating
on a sea of review ink. Your concern that an amp has enough current not
to become unstable for a given spl is fine but not the reason for the
test. The condition in the test that says the amps under test don't
exceed stable limits is obvious, we don't want the 10 k amp wimping out on
us so it sounds different for it's overloaded artifacts and thus easily
identified. Your concern is a rather easy calculation done comparing
lowest speaker load and the current limits of the amp, it is a universe
away from and not relevent in the least to the reason for the test to
exist. Your purchase concern is only about numbers, findd any two amps
with similar numbers and you are home free and no difference in sound will
be found.

Archived from groups: rec.audio.high-end (More info?)

"Yes - this makes this sort f test rather useless in information or
enlightenment.

If I buy sme Maggie 3.6R's I has better get an amp with more cajones than
the Yamaha integrated, for instance.

If I get a Lowther horn speaker - I would do with a lot less power.

I do not see how this "challenge" serves anyone but the ego of the
"debunker"..."

And whose ego is served by restatements of the truism that various
speakers have various current demands at the extremes, which was never at
issue? Whose ego is served by inserting red herrings into the discussion?
Whose ego is served by arguing apples and oranges and distorting the
reasons for the tests being done and concluding one's purchasing decisions
have not therefore been served. And most important, whose ego is served
if one can now conclude that the ego of another is not at issue either and
can be ignored as irrelevant?

Archived from groups: rec.audio.high-end (More info?)

On Sun, 25 Apr 2004 23:40:59 GMT, Bromo <bromo@ix.netcom.com> wrote:

>On 4/25/04 7:20 PM, in article jJXic.34947$aQ6.1879434@attbi_s51, "Stewart
>Pinkerton" <patent3@dircon.co.uk> wrote:
>
>> On 25 Apr 2004 14:15:44 GMT, Bromo <bromo@ix.netcom.com> wrote:
>>
>>> The time and effort might be spent a bit more productively - perhaps trying
>>> to research and measure all sources of sonic imperfections not already known
>>> - pushing the forefront of hearing sciences, and so on.
>>
>> Actually, since we can already prove that dozens of amplifiers sound
>> exactly the same below the clipping point, the time and effort would
>> most definitely be better spent in selecting better speakers, and
>> placing them in the best position in a well-sorted room.
>
>I agree that is a good use of an end user's time and money - but still - if
>people claim to hear a difference, it might be good to do the due diligence
>as a scientific sort to see if there is anything to these claims. Some have
>been made in the past that haven't helped, but some has been made that did.

That is the exact purpose of the various amp and cable challenges.

>> Of course, this would destroy 90% of 'high end' mythology - but
>> perhaps the world would be a better place for that............
>
>Mythology is bad - but I would be careful to discard the grain of truth with
>it. Even if the golden eared claimants were incorrect for the reasons
>*they* said - there might be something there important for sound
>reproduction that they didn't realize.

Interesting that, despite your apparent (and quite reasonable)
standpoint that adequate power is all that matters, you are *still*
buying into the notion that there may be some 'magical' ingredient
that we just don't know about. The real truth is, that P.T. Barnum is
alive and well................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Archived from groups: rec.audio.high-end (More info?)

"Nousaine" <nousaine@aol.com> wrote in message
news:xHXic.34068$w96.2423643@attbi_s54...
> Bromo bromo@ix.netcom.com wrote:
>
> >On 4/24/04 1:03 PM, in article P5xic.20708$aQ6.1263449@attbi_s51,
"Nousaine"
> ><nousaine@aol.com> wrote:
> >

>snip<

> >It is understood by anyone that if you do not feed the speaker with
enough
> >power, it won't sound good - too much power, and you will blow it out.
> >Conventional measurements should indicate if the speaker is likely to be
> >suitable, but to think we understand hearing and the processing our
brains
> >go through to change pressure to sound to make it an end game is pure
> >arrogance to me!
>
> IMO if there were anything to amp sound that is not readily observable
with
> traditional measurements and methods then the Richard Clark Challenge
should
> have brought it to light.
>

Would you please indicate where in Stereophile's set of conventional
measurement the "microphony" test resides that clearly shows microphony as
the reason tube amps are preferred by many audiophiles, as objectivists love
to proclaim loudly and often here.

Archived from groups: rec.audio.high-end (More info?)

Bromo <bromo@ix.netcom.com> wrote in message
news:<c6h4dp0rnp@news3.newsguy.com>...
> I am looking at a Halcro Ad on this month's Stereophile (pg. 15, May '04)
> right now...If you measure any deviation in the RIAA curve...you have
> caught them in a lie and you can feel confident in debunking them.

You can my measurement of the Halcro dm10's RIAA error in our on-line
review reprint: http://www.stereophile.com/amplifi [...] dex5.html.
The deviation from the specificed curve is indeed minimal, other than
the incorporation of the IEC-specified low-frequency rolloff.

John Atkinson
Editor, Stereophile

Archived from groups: rec.audio.high-end (More info?)

On 4/26/04 1:34 PM, in article zKbjc.41838$IW1.2009846@attbi_s52, "Stewart
Pinkerton" <patent3@dircon.co.uk> wrote:

>> I agree that is a good use of an end user's time and money - but still - if
>> people claim to hear a difference, it might be good to do the due diligence
>> as a scientific sort to see if there is anything to these claims. Some have
>> been made in the past that haven't helped, but some has been made that did.
>
> That is the exact purpose of the various amp and cable challenges.

The problem is that it is *not* due diligence, but grandstanding rather
loudly !

Real due diligence wopuld involve getting the amplifiers in question and
doing both double blind testing with a variety of speaker systems and a
variety of sonic and electrical measurements.

Not some silly $10k "challenge"

Archived from groups: rec.audio.high-end (More info?)

"Harry Lavo" harry.lavo@rcn.com wrote:



>
>"Nousaine" <nousaine@aol.com> wrote in message
>news:xHXic.34068$w96.2423643@attbi_s54...
>> Bromo bromo@ix.netcom.com wrote:
>>
>> >On 4/24/04 1:03 PM, in article P5xic.20708$aQ6.1263449@attbi_s51,
>"Nousaine"
>> ><nousaine@aol.com> wrote:
>> >
>
>>snip<
>
>> >It is understood by anyone that if you do not feed the speaker with
>enough
>> >power, it won't sound good - too much power, and you will blow it out.
>> >Conventional measurements should indicate if the speaker is likely to be
>> >suitable, but to think we understand hearing and the processing our
>brains
>> >go through to change pressure to sound to make it an end game is pure
>> >arrogance to me!
>>
>> IMO if there were anything to amp sound that is not readily observable
>with
>> traditional measurements and methods then the Richard Clark Challenge
>should
>> have brought it to light.
>>
>
>Would you please indicate where in Stereophile's set of conventional
>measurement the "microphony" test resides that clearly shows microphony as
>the reason tube amps are preferred by many audiophiles, as objectivists love
>to proclaim loudly and often here.

It would seem to me that the frequency response anomalies that come with
high-output impedance amplifiers completely describe any audible differences in
tubed amplifiers.

As far as the microphony "issue" it seems to me like one you just made up
yourself.

Archived from groups: rec.audio.high-end (More info?)

much snipped...
>
> We've done enough testing of specific claims to have laid that idea to rest.
> There is no underground grain-of-truth resting just below the surface. If there
> were then someone, somewhere would have stumbled on it over the past 30 years
> of searching.

Tom,

I agree that there is not much that differs amps during music
listening and using 99.9% of loudspeakers of the market, and standard
DBT testing. But if one wants to find out any putative difference, the
test methodology needs to be the most sensitive around. The
before/after listening tests are far more sensitive that just
comparing two amps A/B, since you are comparing the amp with a bypass
cable (the "before" signal). I've posted the link before:

http://www.sonicdesign.se/amptest.htm

I am not saying that there will be audible differences when comparing
the traditional DBT way, but putting things to "rest" does not mean
that there are differences, explained by physical terms, that can be
judged to be significant different. It will, however, have probably
have little practical meaning for the user. It can also be a
preference to have an amp where the spec are far below the audible
limit thereby it will warrant such a market. (I am not talking about
expensive amps which have poor spec here, but those having high-end
spec and thus in general more expensive.)

T