(Thomas A) wrote:

(Nousaine) wrote in message
news:_0Bjc.31128$0u6.5483536@attbi_s03...
(Thomas A) wrote:

much snipped...

We've done enough testing of specific claims to have laid that idea to
rest.
There is no underground grain-of-truth resting just below the surface.
If
there
were then someone, somewhere would have stumbled on it over the past 30
years
of searching.

Tom,

I agree that there is not much that differs amps during music
listening and using 99.9% of loudspeakers of the market, and standard
DBT testing. But if one wants to find out any putative difference, the
test methodology needs to be the most sensitive around. The
before/after listening tests are far more sensitive that just
comparing two amps A/B, since you are comparing the amp with a bypass
cable (the "before" signal). I've posted the link befo

http://www.sonicdesign.se/amptest.htm

I am not saying that there will be audible differences when comparing
the traditional DBT way, but putting things to "rest" does not mean
that there are differences, explained by physical terms, that can be
judged to be significant different. It will, however, have probably
have little practical meaning for the user. It can also be a
preference to have an amp where the spec are far below the audible
limit thereby it will warrant such a market. (I am not talking about
expensive amps which have poor spec here, but those having high-end
spec and thus in general more expensive.)

T

The wire bypass test is a good idea. In fact, Arny Kreuger's pcabx is
precisely
that. But the site's "data" is simply a statement.

But taken in context wouldn't you say that all the cable-swap and switched
test
results would tend to show that if it is true as the site claims that if
nearly
90% of amplifiers are not straight wires with gain into his simulayed load
they
must nearly universally have the same errors.

Tom,

I don't think they are saying that every amp has the same errors, but
they can probably be divided into a few "groups". I've not read all
the different tests that have been conducted during the years, but
usually, the amps coming up to be transparent (or very close) are e.g.
NAD 208 THX and Rotel RB 1090.

The recommended list of equipment is he

http://www.lts.a.se/teknik/rekommenderat.html

Although it is in Swedish it is probably not difficult to understand
which components that are "recommended".

T

Sorry I wasn't a bit more clear. If, as this sire claimed, 8 of 9 amplifiers
could be distinguished from a straight wire when their output was played
through a 2nd amplifier then amplifiers 'different' sounding than a piece of
wire are common.

However, there have been a couple dozen bias-controlled listening tests of
amplifiers which have only found amplifiers with a lack of competence
(frequency response, overload or other operating errors) to sound different
from one another.

So putting these two data set together I would think that all those amplifiers
that sound different from a piece of wire (90%) but do not show up as being
different sounding from each other in other tests must have errors with enough
similarity that they sound like each other even if they don't sound identical
to a piece of wire.