I said


No it is not. Analogies to highly inflamatory subjects is nothing but
insulting. claiming that different amplifiers may sound different
is not a claim of paranormal phenomenon per se.


Tom said


It's an extraordinary claim that has not been verified by any bias
controlled
experiment.

I said


It is not an extraordinary claim and it has been observed in bias
controled
tests.

Tom said


It is an extraordinary claim because it has ONLY been observed in
bias-controlled tests when a known audibility element was also either
verified or likely.

I don't follow your logic. The claim of amplifier sound cannot possibly be so
extraoridnary if it has been conceded that it has happened. If it has been
observered in bias controled tests regardless if the reasons are known or
unknown it is ridiculous to say it is an extraordinary claim.


Tom said

There's been NO replication by any interested party that cannot be
fully explained by the exitsing evidence on human hearing perception.

As before.

I said


There has been no replication of the tests you have cited either.


Tom said


I beg your pardon. There have been a couple dozen replications.


None that I have seen. Every test you cited was different in many significant
ways. That would not constitute replication. So, if any of the tests you have
cited have been truely replicated then you haven't cited the replication of
these tests. The articles inwhich they were published do not cite any such
replication.

I said


Further more no one is saying that differences between amps are
inexpicable.


Tom said


That's right. They come to a few selected elements and can be
verified. If are you agreeing that an amplifier with flat response at the
speaker
terminals not driven into overload more than 1% of the time will be
transparent
then what's left to argue?

I am agreeing that if amplifiers sound different those differences are
measurable. I am not limmiting the source of all audible distortions in
amplifiers to frequency response. If you are claiming that it has been proven
that the only audible distortion from an amp is in the frequency response then
i would like to know how you know this to be a fact?


Tom said


So, yes, it's like a claim of anti-gravity.

I said


Yes you are. You are saying that claims of audible distortion in amps
is a
claim of the paranormal. IMO it is a completely unreasonable
rhetorical claim meant as a campaign for an agenda rather than a logical
claim based
of established facts.

Tom said

The established facts are that humans hear loudness, pitch (as jj
would say
partial loudness differences) and timing (direction.)
When an amplification device provides a signal to the speaker
terminals that does nothing more than uniformly raise the level of the signal
applied
to its input terminals it will be perfectly transparent to a listener. ie
impart no
sound of its own.

I would agree with that. Get back to me when such an amp exists.

Tom said


It is well known that modern amplifiers of competent design are
generally capable of doing this within their power limits into normally
encountered, and even ‘difficult’ load conditions.


Well I have heard differently. I have heard that amps distort the signal in
many different ways and each amp measures quite differently. The question is
what is the audible threshold of each and every distortion prosduced by any
given amp when driving any kind of real world speaker load.

Tom said


For an amplifier to impart its own sound it must find a way to
desecrate the signal ....damage it in some way by adding distortion or
changing the
partial loudness curve.


Agreed. But I think your apparent claim that amps don't distort the signal is a
gross misrepresentation of the facts.

Tom said


To say that amplifiers, as a class, are not capable of this other than
violating the stated conditions is a claim that is directly analagous
to making claims of para-normality.

No one I know of is saying that amplifier sound is anything but distortion. So
who are you arguing with on this issue? Who is claiming that amp sound is
magical? I certainly am not. I agree that any sound that an amp may have is a
result of measurable distortion. That is not an extraordinary claim. Maybe our
argument will make progress if you avoid building false positions to argue
against.

Tom said


If we want to 'warp' the response of the loudspeaker an equalizer is a much
better method than using an incompetent amplifier which will normally
supply incompetence through a high-output impedance.


I fail to see the relevance of this point. My point was that without
scientifically valid evidence one cannot make claims one way or another about
the sound of amplifiers and rightly claim their position is supported by
science.

Tom said


Now IF you're claiming that extra-normal amp 'sound' is a function of
non-amplification irregularities (frequency response or overload
errors) into a given load then we all "agree" on what "amp sound" is.

I think I have been more than clear about my claim on this thread. See above.

Tom said


But you appear to be making a more global statement. That clipping and
frequency response errors are NOT the basic fabric of 'amp' sound.
This is extraordinary.

I don't know why you are having such trouble understanding my simple claim in
this thread so I will say it again at the risk of being painfully redundant.
Without scientifically valid evidence one cannot make claims one way or another
about the sound of amplifiers and rightly claim their position is supported by
science.
How you can deduct that out of this claim I am, as you say "But you appear to
be making a more global statement. That clipping and frequency response errors
are NOT the basic fabric of 'amp' sound. This is extraordinary." is beyond me.
I just don't see it. It looks like a lot a straw man arguments that are totally
unrelated to my very simple straight forward point.

Tom said


If you are NOT making a statement like this then we have no
disagreement.

I am not making any statements as to the cause of amplifier sound.


Tom said

It doesn't fit with present
experimental evidence.


I said


No. It doesn't fit with some anecdotal exerimental evidence. You are
still
picking and choosing your evidence hear and placing far greater
wieght on
that
anecdotal evidence than it is due.

Tom said


So statements of 'amp sound' without bias controls carry the same
weight as experiments that have applied these experimental protocols?
I strongly disagree.


I never said that. I simply said they failed to make the grade for scientific
validity. OTOH I see nothing to suggest the very tests Stewert did were in any
way inferior or less reliable than the ones you cite as valid scientific proof
about the amplifier sound.

Tom said


Do you have a reference to a peer-reviewed experiment on Alien
Abductions to
report?


I said


Yes.

J Abnorm Psychol. 2002 Aug;111(3):455-61.

Memory distortion in people reporting abduction by aliens.

Clancy SA, McNally RJ, Schacter DL, Lenzenweger MF, Pitman RK.


Tom said


But that didn't investigate the abductions. It appears to be reporting
on people who have reported abductions. I see nothing here to suggest that
the
abductions
themselves have been investigated.

It was what you asked for. It was a peer reviewed experiment on Alien
abductions. More precisely it investigated the cause for the claim of alien
abductions.

Tom said


My paper "Can You Trust Your Ears?" is of the same nature.

Really? What peer reviewed scientific journal was it published in?

Tom said

People who
are given the same sound presentations are very prone to report them as
different. e.g. report distorted versions of reality. I'm glad you brought
this up because appears to
illustrate my point quite well.

So? I have not disputed the fact that biases affect perception. The same is
true when people listen to speakers. It doesn't lead to the conclusion that
speakers all sound the same does it? Just because some people are reporting
differences that may have been the result of sighted biases doesn't prove that
all amps sound the same.


I said


There certainly are plenty of published investigations on claims
of paranormal activity. They found nothing paranormal.


Tom said



Isn't that surprising? Do you have some peer-reviewed references?


I said


I can find them if you like. Just as I found the one above on alien
abductions.

Tom said


But you didn't find a peer reviewed article that investigated the
existance of abductions (amp sound) now did you?

Yes I did. The investigation showed a likely cause of claims of alien
abductions without the need of aliens abducting people. So it did in effect
investigate the validity of such claims in light of the complete absense of
forensic evidence and third party eyewitness acounts.

Tom said

You only found one examining
memory distortions of reporting on them.


I found what you asked for and now you want to redifine what you asked for.
forget about the offer to find anything else on the subject. It is clearly a
waste of time. Now please feel free to get back to me when you can cite any
peer reviewed published data that support your position on amplifier sound that
you seem to claim is supported by science.

I said

No, what happened is no one has published any tests in the AESJ.
Articles
have
been published supporting the use of bias controled tests when
comparing amps
and the like so it is hard to say the AESJ is completely
disinterested in the
results of such tests. Yes it would
pobably be very uninteresting to
go out
looking for bigfoot, find nothing and then publish that you found
nothing.


Tom said

When
one does scientifically valid tests on amplifier sound one never finds
nothing.
They find the amps to be indistinguishable or distinguishable. Either
way,
there is data to report that can be seen as valuable to audio
engineers.

Tom said


This has been reported. Toole published the first one in 1976. Two
dozen others followed. What more is needed?

Published where?

I said


In
all
those tests on human thresholds of hearing they do reprot what is
inaudible
do
they not?

Tom said



Good point. But the current work is on data reduction. All the work is
supported by bias controlled listening tests published or otherwise.

Which supports my claim that in the absense of any peer reviewed tests on the
sound of amplifiers one cannot make global definitive claims one way or another
and rightly claim that science supports their claim.