Dynamic phase shift
"Phil"
Andre Jute wrote:
We're
not talking about "-30 degrees at 20 KHz," we're talking *dynamic* phase
shifting, the kind that makes a Crown preamp bite your ears off, while
testing at 0.0001% THD.
Let's hear some more about this dynamic phase shift that pours a pint
of vinegar into a Crown preamp. I'm not overimpressed with vanishign
THD but this is an amazing explanation for why so many silicon amps,
and not a few tube amps, sound like ****.
Pretty much what Patrick said, although I need to reply in the original
thread. What Matti Otala PROVED --
** Otala never proved one, single commercial hi-fi amp suffered from TIM in
a way that was audible.
Many others have proved conclusively that TIM ( ad his cousin SID) is a
furphy.
and Dr. Ottala was up there with Richard Heyser, not just a professor, but
the Director of the Technical Research Center of Finland, and the guy who
published many of the original papers on TIM (transient Intermodulation
Distortion), so what he said should at least *intially* be taken seriously
** It was - then got utterly debunked by others in the field wordwide.
The debunking unfortunately did get the NOT the same publicity as Otala's
hypothesis.
So, ignorant ****WITS like you never heard about it.
-- was that the
amplitude distortions of the open loop are transformed into phase
distortions of the closed loop, where the low frequency signals phase
modulate the high frequency signals. I *think* this means that the high
frequency signals move back and forward in time in the presense of low
frequency signals, something that is actually quite difficult to measure,
although all too easy to hear.
** Such and effect would be extremely easy to measure
It just don't exist when musical programme signals are being reproduced.
It has some rather interesting implications about feedback,
** ******** it does.
In "The Audio Critic," Vol 2, #2, 1979, p 37, Peter Aczel said Otala's
technical paper was to be delivered on Feb. 25, 1980,
** That was a very long time ago - ****WIT.
........ Phil
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