"Bruce Abrams" wrote in message
...
"Harry Lavo" wrote in message
news:KvA0c.152472$jk2.593654@attbi_s53...
*snip*

Michael, I and others have described similar tests here under similar
conditions, and have always been told we are just imagining the
differences
based on "expectation bias". Expectant of what they can't say.

Harry, you know the answer to this question, as it's been repeated ad
nauseum. Expectant that the amps in question sound different.

Unfortunately, some of the members of this forum, while intellectually
understanding it, have a difficult time differentiating between "sight
*may*
provide a bias that overrides true differences" with "sight *always*
overrides true differences and makes your comparison invalid".

If you allow for the fact that sight *may* provide a bias that overrides
true differences than you must control for it, always. Failure to do so
leaves open the possibility that you may have been influenced by sighted
bias. There would simply be no way to know whether the listening results
were valid or bias influenced, and no amount of arm waving shouting "DON'T
TELL ME WHAT I HEARD" will change that fact. Bias controls are necessary
not because the biases always exist, but exactly because they may exist.

The are not *NEEDED* for home audio purchases and comparisons as long as the
person doing the comparison is willing to accept some risk. And
expectation bias as postulated has to be stretched to the extreme to cover
five amps with four different "sounds".

This part of this thread started rather interestingly with Michael asserting
that Occam's Razor suggested that the simplest explanation for people
claiming to hear amp and cable differences was that the differences exist.
Stewart and Steven both jumped in to claim that, no, Occam's Razor suggested
expectation bias as the likely culprit. However, neither explained to
Michael what expectation bias was. They just flat out asserted that he was
wrong. Later when Michael asserted that he had heard differences in his amp
test, he was gently told by Steven that his results might not be real. But
by then the "negativity" had set in and a battle was on.

Michael's type of comparative test is one many audiophiles have done for
themselves at times..a shootout comparison. Not the most scientific. But
there is nothing in such a shootout to assign sound character to the amps,
as Michael points out. The worst expectation bias can do is to make one
assume differences exist. He has already said that for one pairing the
differences where very small. Perhaps expectation bias might have clouded
an otherwise identical verdict. But it is hard to explain his other
descriptions as being based on expectation bias. As he has tried to point
out.

And as I have tried to point out elsewhere, this "sighted bias" stuff is
often used in a negative way and without any real consideration given to its
applicability. In my opinion, it is often overused here a s a "club" and to
show off. Educating people is fine. Picking fights or debates with them
without even explaining your terms is not so terrific.

For what it is worth, I am probably familiar with two of the amps he tested
(by knowing the brand) and would agree with his characterization of the
sound if they were the amps I heard. Not that that is definitive in any
way, but it may mean these brands do have a characteristic sound and that he
heard
them. Or perhaps we are just two small parts of a mass delusion.