"Andrew Haley" wrote in message
...
Harry Lavo writes:

As a specific example, I recently bought a used power amp by a
manufacturer
based on my satisfaction with another piece of gear from the same range
by
that same manufactur. It was hopefully to replace a piece of gear that
I
had been relatively happy with, but I felt was slightly lacking in a
specific regard. When I got the unit, I pulled out a few "test" disks
and
substitued the units back and forth, playing and replaying sections from
the
disks. My overall evaluation was that the units sounded essentially
alike
in frequency response and speaker control, and the new unit had the
characteristic I had been looking for (also good). So I was predisposed
to
keep/like the unit. I put it in the system and used it as I worked at
the
computer for a week...but I noticed that I became tired of listening and
slightly irritated after several hours..that had never happened with the
old
unit. Switched it back in, went another week, no problem. Put the "new"
unit back in, another few days...same irritation problem. Back in went
the
old...no problem..and it is staying there and I am selling the new unit.
If
anything my expectation bias was that I would like the new unit, and
the
comparative testing tended to support this. But clearly long term there
is
a problem and it is a piece of gear I cannot live with.

What I can't understand is this: what leads you to believe that this
irritation had anything to do with the actual *sound* of the used
power amp? It could surely have been caused by all manner of things.

I don't understand it either but the fact of the matter is that my
experience parallels that of Mr. Lavo (exactly). A/B/X.../Y/Z,
blind, etc. mean absolutely nothing to me. I have often been ridiculed for
my belief, having been informed that an instant comparison tells the whole
story. I have to live with a component in my system for at least a week
before I learn whether or not I'm *comfortable* with it. Like most other
things in life, perhaps I have a liking for some characteristic upon first
consideration, but after a longer time a learn it's unlivable. At very least
this long term evaluation rules out minute differences in volume level as
being responsible for one's preferences,