Poopie Stevenson says he came to RAT to learn. He won't learn anything
by abusing as morons the leading men, who've all done many times what
Poopie is trying to learn to do,. Yet that is what Poopie has been
doing for the four or five years since he arrived on RAT promising to
be "on your arse". RAT, for those who don't know, is a thermionic tube/
valve conference.
Since no one has yet told Poopie that the way to learn to do what we
do is not by abusing us, let me be the first. But let us not just be
negative, in the style of Poopie himself, or his fellow-traveller,
Booger Krueger, or the late unlamented Stinko Pinkerton. Let us be
positive.
Let us offer Poopie the education he seeks. Now, the problem with
Poopie, as with a lot of other diplomaed quarterwits who grandly style
themselves "engineers" when they're really not very bright but very
jumped-up technicians, is that they have without thought learned so
many counterproductive tenets (that's a euphemism; the non-PC may read
"prejudices") that they will never build a good tube amp (or a good
anything) unless these deeply held beliefs, misrepresented by the
diplomaed quarterwits as "facts", are broken down and deleted for
ever.
So, before Poopie can achieve his heart's desire of becoming a tube
designeer, he must first agree to these truths, which he may find
shocking:
1. THD doesn't predict whether an amplifier will sound right or not.
THD is today a totally irrelevant parameter.
2. IMD, while theoretically a more useful parameter than THD, is still
too coarse to predict the quality of an amplifier.
3. The damping factor (DF) really doesn't mean **** because speakers
are too variable.
4. Ears, educated at live concerts, are better measuring instruments
than anything B&K ever built.
5. Blind listening tests with qualified panels are the final arbiters
of audio quality whereas instruments and normative assumptions (1-3
above -- a normative assumption is "what should be" rather than "what
is") can never be the final arbiters.
6. NFB is not the answer.
7. Psychology is one of the answers.
7. Residual harmonics of 2HD are harmless up to half or three-quarters
of one per cent. Third and higher harmonic distortion is destructive
of quality sound even at minuscule fractions of one per cent.
8. There is no such thing as "SE sound". The so-called "SE sound" is
made by Class A1 triodes operating with very little or zero negative
feedback. It doesn't matter if those tubes are operated single-ended
or in push-pull, and it doesn't matter whether they are real real
triodes or triode-tied pentodes. It doesn't even matter particularly
whether they are DHT; the distinctive, pleasing purity of that sound
comes from Class A1 and the absence of third and higher harmonics
which accompany the absence of NFB.
9. The loudspeaker is responsible for 95% of sound quality.
10. The best-sounding loudspeakers are point sources or faux point
sources like fullrange horns and the Quad ESL63 and its successors.
Multiple cones are the work of the devil.
Once Poopie has mastered the first ten commandments, we can continue
with the rest of his education.
Andre Jute
Visit Jute on Amps at
http://members.lycos.co.uk/fiultra/
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