On Sun, 9 Jan 2005 16:30:51 -0000, "Richard Wall"
wrote:

Hi Fi manufacturers are the same as any. They change things for two
purposes. First is to make them cheaper to improve the margins. Second
is to make them appear different so that not only new buyers but old
ones will purchase the new item.

There is of course absolutely no need to make them sound different -
actual improvement ceased long ago - while one-upmanship and other
psychological effects do such a fine job without effort on the part of
the manufacturer.
I cannot agree, unless you can name a price point above which this might be
true. Low cost componants sound substantially different than better made
ones. I would have no problem spotting the difference between my Pioneer
DVD565A on CD alone and via my DAC64 in any test.

Care to put that to the test, when you don't *know* which output is
connected, and they've been level-matched?

Cheap CD/DVD players
usually are cheap, and are compromised. I wouild assume the same to be true
of cheap amps vs better built products.

And we all know what 'assume' does................ :-)

The differences between "good amps"
are very small and could easily be tweaks to make them suit listening
choices. I have recently compared my Vocale SET, a Pass Labs Aleph 3 and a
Prototype amp that may soon be sold by Revolver. The prototype sounded
dreadful until we found that the volume pot used degraded the sound at its
highest attenuation essential for my 103dB efficient speakers. Once the
prototype was properly attenated I would not be certain that I could
consistantly spot the difference between the three.

Quite so - and the same applies to modern CD players.

I think amplifiers and CD/DVD players etc. sound different because we have
not yet achieved perfect reproduction of the recorded medium. So called
"good" componants are very close to perfect and differentiating by any
method will be difficult. Rather than the image of a straight line with
amplification from source to speakers I view a system as a filter with
amplification between source and speakers. The better the filter the less
it removes/adds and the closer to perfection it gets. It is still possible
to measure electronicly differences in amplifiers and also to make them
react to inputs in in different ways ( e.g. slew rate (?)) There are even
different topographies Class A, AB and I think C and D. DBT should and I am
sure can differentiate some of these classes of products if it cannot then
the testing method must surely be faulty ?

Why would you *assume* that class of operation matters (aside from
class C, of course!) to the sound of an amplifier? While it's true
that most SET amps sound dreadful, that's not because they operate in
class A. All good amps *do* sound the same, and there's nothing wrong
with double-blind ABX testing which shows that to be true.

The one area where none of the above applies is the loudspeaker, which
is still frankly a disgrace. You don't need a DBT to reveal the
differences between speakers, and unlike the other stuff, the
differences persist under DBT conditions.

As for DBTs usually succeeding - it is simply true. It is very easy to
run a good DBT. But maybe my definition of success is not the same as
yours. Mine is that the DBT reveals the truth, whatever that is. Maybe
you consider a DBT to have failed if it does not show a difference?
That would be a reasonable conclusion to your assertion that DBTs
don't work for Hi Fi. If things cannot be differentiated in DBT, it is
because they actually aren't different.

My critism of DBT is that it is not simple to set up in a domestic
enviroment

Sure it is, especially when compared with setting up a Linn Sondek!

and of the few test I have heard of that finds differences
(recent issue of Hi-Fi Plus on cables ?) the conditions of the test are then
questioned.

Rightly so, since that was *not* a DBT.

The advocates of DBT/ABX all seem convinced that there are no
differences between CD players, cables and amps, those more open qualify
this with a definition of "good" componants.

I have in fact never seen *anyone* claim that *all* CD players and
amps sound the same, although I agree that the good ones do - as you'd
expect. OTOH, wire *is* just wire, unless you *really* mess up the
basic electrical parameters.

I am happy to agree that when
talking about "good" components any differences will be minor and most
likely built in by a manufacturer looking to differentiate their product
from the rest. Hearing a difference in a blind test will be unlikely. What
I question is that a lot of current equipment does not meet the "good"
criteria and it does not take a blind test to prove this.

Never argued - and particularly true as the price goes up!

If DBT/ABX does
fail to differentiate products that sound different then why does it fail,

It doesn't...................

my suggestion is that the detection method used (the listener) is too
subjective

That's why it's a *blind* test. Duhh...........

and without a massive sampling set any results are no better at
providing proof than simple A-B.

Richard
New Ash Green Hi-Fi Club

Why don't you encourage the club to run level-matched ABX sessions, if
you're *really* interested in the truth? One test setup would then be
shared among all the members, and you'd also have a larger sample.
--

Stewart Pinkerton | Music is Art - Audio is Engineering