[William Noble]

"Sonnova" wrote in message
...
On Tue, 14 Oct 2008 05:35:00 -0700, William Noble wrote
(in article ):

sniip


5. I have done tests where I lined up a pile of power amps, for
example,
a
10 watt Leak, a 35 watt Fischer, a 60 watt dynaco, a 350 watt kenwood -
using the speakers I had at the time (AR-3) and the music I liked at
the
time (don't remember what I used), there was no question that the
quality
of
the resultant sound improved with power - the low end went from muddy
to
crisp. A 700 watt amp that I tried was one notch better, but beyond my
budget. I'm not going to debate this, you may hear differently, this
is
what I hear, at the same very soft volume level.

Using the amps that you used, I suspect that the Leak, probably the
Fisher,
and perhaps the Dynaco (unless it was a ST120 rather than a Mk.III, you
don't
say) were tube (valve) amps. if so, the bass quality difference has as
much
to do with output transformers in the tube gear vs solid-state (the
Kenwood
and perhaps the the Dynaco - if its a solid-state amp), as it has to do
with
power.

you may well be correct about the root cause of the improvement - I
actually
expected the Leak to sound the best, it certainly had the best
reputation.
As I think back, I think I had two dynacos - one was a 50 watt tube unit
(mono), the other was a stereo 120. Nonetheless, tubes or not, with my
speakers (AR3a) and my source (marantz 7T and a turntable - I don't
remember
the cartige now), sound quality, particularly at the low end, at VERY
SOFT
volume, was directly proportional to power. As I stated somewhere else,
this finding was the exact opposite of what I expected, and I repeated it
over and over to prove it to myself, so I doubt that preconceived bias
had
much to do with the conclusion

AR3s? That explains it. 15 Watts is nowhere near enough power to satisfy
the
requirements of an AR3. It was a VERY inefficient loudspeaker that
required,
IIRC, at least 25 watts/channel to drive it. The leak was likely clipping
most of the time! Of course it sounded bad.

negative - I certainly know clipping when I hear it - none of the amplifiers
was clipping, ever. all listening in these tests was done very softly. and
as I said, I got the opposite results I expected. The AR 3 was rated at 40
watts minimum. increasing power up to 700 watts per channel was audible -
and I am talking about playing the sound at a very low, nearly a wisper,
volume.


snip


the statement above about "practically identical" is misleading. it all
depends on what you mean by "practical". When I bought my Mark Levison
power amp (No 332), it replaced my trusty Kenwood 700M - they have
aproximately equivalent power and seemingly similar specs, though the ML
unit is quite a bit heavier. The difference was clearly audible. I
tried
other power amps also, some sounded better still, but I didn't feel they
were worth the $$. I would argue that all of the amps I listened to were
"properly" designed, but there were clearly audible differences. My test
CD
for all of these tests was a song from Gillian Welch's Hell among the
yearlings album, played very softly - in no case would it have been hard
to
talk in a normal voice and be clearly heard - I used ReQuest speakers for
the test - maybe some amps don't like those speakers, but it was what
I've
got.

Of course the ML sounded better than the Kenwood. You just bought it, paid
a
ton of money for it, and your expectations were high. New is always going
to
sound better than "old" that's why sighted evaluations - especially by the
owner of the new gear - are so unreliable. Connect those amps to your
speakers using an A-B switching device, match the levels to within 1/4 of
dB,
and have someone else randomly switch between them (where you can't see
them
doing it) while you listen, and then come back and tell us which amp was
which. As long as neither amp is being driven outside of its capabilities
and
as long as the Kenwood (which, I take was rather old, since Kenwood hasn't
been sold here for many years and is called "Trio" in the rest of the
world)
is in original working order (no tired capacitors) then I doubt seriously
if
you could tell the difference.

well, you are certainly entitled to your opinion - however, I brought the
kenwood to the store and in fact did exactly the AB switching you suggest,
and both me, and my wife clearly heard an improvement that we felt was
significant. So, 1. I had NOT bought the amp or paid anything for it when I
did the test, and 2. the difference was clearly audible to those who
listened. I am sure that there was no bias in noting a difference. Whether
YOU could hear the difference is not something I can remark on. Did I want
to hear a difference? - actually, no, I would have preferred to not hear a
difference, it would have saved me buying a new amplifier - It is certainly
possible that specific components in the Kenwood had degraded, though I
suspect that the difference was actually in the damping factor achieved.

I will also note that I was ABSOLUTELY convinced that changing interconnect
cables would make no difference in the sound, and I proved myself wrong.
The most striking double blind test in this situation took place when I had
pretty much settled on a particular set of cables and tried an alternative
set - shortly after I had switched them and was again listening to the same
song, my daughter, who had been outside in the back yard the whole time
walked by to go to the front and noted "oh, you switched the cables again, I
don't like this one" - she had absolutely no way of knowing this. I am sure
some will doubt - be my guest. I posted detailed comparisons of the various
cables I tried, both commercially built and ones I built on this NG at the
time - probably 5 to 7 years ago.


So, I can't argue subjective experience, I can only report my experience.
I
do agree that the power amp is one of the parts that has the least
overall
effect once you get a "good enough" one, and that the improvement going
from
a $500 amp to a $250,000 amp is smaller by far than is gained by going
from
a $500 preamp to a $5000 preamp.

I'm not even sure that's particularly true.

your opinion is noted, I've offered mine. I offer my experiments and
experience as backup to help the OP decide what to do. the OP may choose to
accept or not accept that which I offer.