In article , Serge Auckland
wrote:



I think that the explanation is fairly simple:- The Quad tests were
done with a Quad II valve, and 303 and 405 SS. All three amplifiers
perform to a level that is below the threshold of audibility for
frequency response errors, noise and distortion, consequently will
sound the same into the load they were presented with at the tests
(Yamaha NS1000). This will be true of any amplifiers who's performance
below the audibility threshold. I don't think there is any mystery
there.

Actually, I and some others found the results of the 'Quad' test quite
interesting at the time. This was for two reasons.

1) That although the three amps were all 'Quad' designs, their specs in
terms of things like frequency response *on load* were different. (Indeed,
in the later tests organised by Colloms this particular point came in for
some scrutiny. Yet the second set of tests also produced evidence that the
listeners could not tell one amp from another in the tests.)

2) That all along PJW was confident that people would *not* be able to tell
the difference despite (1) and the loud claims of reviewers before the
event that thy would be able to do so. People may nowdays forget that PJW
spent many a long year involved with developing the amps, and other kit,
and was also an keen amateur musician. He did listen to the equipment and
was a stern critic. Yet he held no sympathy for the claims of the reviewers
which the tests refuted.

The later 'Colloms' test was even more interesting as it used an even
wider spread of amplifier types, and more demanding conditions of test,
yet gave similar results to the 'Quad' test.

Slainte,

Jim

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