[Premium-Rx] DSP -v- analogue

[Michael O'Beirne]

Good evening all.

I agree wholeheartedly with Gary's piece this evening.

There is the added factor that human perception is incredible difficult to
analyse and measure.  Resistors are unthinking and will follow Ohms Law 
regardless and receivers will
follow the IP3 rules but we humans are umpteen times more sophisticated in
the way we function and seldom function entirely as predicted.  How can any
machine sensibly compare the tonal qualities of a Yahama piano with a
Broadwood with a Steinway?  Of course one can take spectrum measurements but
what do they prove?  As I type this I am listening to a relay on the BBC of
"Rigoletto" direct from the New York Met.  How can any machine possibly
compare the qualities of the voices of the baritones singing Rigoletto and
Monterone?

Harmonic audio distortion sounds not unpleasant.  As a professional musician
friend of mine told me not long back, this distortion mostly brightens up
the top end of the spectrum.  Sometimes he deliberately adds some to his
"creations" to alter the effect.  This distortion is given mostly by valved
amplifiers.

Intermodulation audio distortion, in contrast, sounds absolutely awful.  I
joke with him that this is "Stockhausen music".  I have read that transistor
amps are far more prone to such distortion.  The ear is particularly
sensitive to this distortion and may react disproportionately to what lab
measurements of IM would suggest.

There are of course the super keen audiophiles with super deep pockets who
are prepared to pay outrageous sums for valved amps.  I saw a review of one
the other day retailing for over £14,000.  Presumably even the rich
bankers/footballers/Russian billionaires and the like would hesitate before
parting with such money unless the quality was unexcelled.

So where is this ramble heading?  Only that technical measurements are but
part of the story.

73s
Michael
G8MOB