Re: [LAU] Pro Audio? OT rant.

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To: <linux-audio-user@...>
Date: Monday, December 24, 2012 - 4:13 pm

On Monday 24 December 2012 10:37:40 Fons Adriaensen did opine:

> On Mon, Dec 24, 2012 at 04:06:32PM +1300, Chris Bannister wrote:

Absolutely. However, the response of a passive filter is 100% predictable.
Enough math applied to that distorted waveform can tell you very accurately
what the bandwidth and group delay characteristics of that path the square
wave followed from the input jack to the output terminals.

There are many other things involved, and there can be, in some amplifiers,
such as the high powered klystron used in tv broadcasting back in the day
of 2 cents a kilowatt electricity, a delay that varies with the power level
precisely because of the relativistic effects imposed on the electron beam
that does the amplifying. It is a beam velocity modulation and because of
the e-mv2 relationship, the positive swing of the input cannot accelerate
the beam quite as much as it can slow it down on the equal negative swing.
So that device is electrically longer at the high power levels of the sync
tip portion of the old ntsc signal. It is also called incidental carrier
phase modulation or ICPM in shorthand speak. And it is not easily
corrected, so the sync waveforms were horribly distorted by having the high
frequency edges moved as much as 200 nanoseconds to the left.

It was also the cause of about a 20 db loss in the aural SNR in the viewers
receiver because the receivers used the intercarrier frequency only in
detecting the sound, that imposed that ICPM as a background buzz in the
audio. I didn't fully understand just how bad it was till a circuit
breaker running the coolant pump failed, single phasing that 3 phase 10hp
motor, and the electron beam burned a hole in the klystrons collector,
filling it with water. That hole was a $150,000 hole, and 2 months running
at low power because I wheeled the 2200 lb aural dolly with an old tired
klystron in it into the visual cabinet, tuned it even more broadband than
usual and, using an N 't", fed some of the aural drive into the visual
tube. So we had about 25% of our normal power on the air. Because with
both signals being subjected to identical ICPM effects, and the receivers
operating on the frequency difference only, the normally 45 db down audio
'sync' buzz was gone, and the on air aural SNR was suddenly close to 72 db!

When the new tube arrived, I almost didn't want to go back to full power
because I knew that &*^*& buzz would be back. I did get comments on it
from the viewers too, they noticed it right away.

> > That test alone made me realise that a simple listening test is not

Yes you can, particularly from the aspect of how good the anti-aliasing
filters are.

> Ciao,

Cheers, Gene
--
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soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: is up!
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Messages in current thread:
[LAU] Pro Audio? OT rant., John Murphy, (Sat Dec 22, 2:58 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sun Dec 23, 1:57 am)
Re: [LAU] Pro Audio? OT rant., John Murphy, (Sun Dec 23, 2:50 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sun Dec 23, 5:42 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sat Dec 22, 3:43 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Sat Dec 22, 5:19 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sat Dec 22, 5:39 pm)
Re: [LAU] Pro Audio? OT rant., John Murphy, (Sat Dec 22, 8:26 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Sat Dec 22, 9:00 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sat Dec 22, 9:16 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Sun Dec 23, 3:21 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sat Dec 22, 5:54 pm)
Re: [LAU] Pro Audio? OT rant., Paul Davis, (Sat Dec 22, 5:44 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sat Dec 22, 6:01 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sun Dec 23, 1:53 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sun Dec 23, 11:33 am)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sun Dec 23, 5:39 pm)
Re: [LAU] Pro Audio? OT rant., Chris Bannister, (Mon Dec 24, 2:43 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Mon Dec 24, 8:59 am)
Re: [LAU] Pro Audio? OT rant., Ricardus Vincente, (Mon Dec 24, 3:13 pm)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Mon Dec 24, 10:22 pm)
Re: [LAU] Pro Audio? OT rant., Neil, (Mon Dec 24, 11:01 pm)
Re: [LAU] Pro Audio? OT rant., Ricardus Vincente, (Mon Dec 24, 11:31 pm)
Re: [LAU] Pro Audio? OT rant., Neil, (Tue Dec 25, 1:34 am)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Tue Dec 25, 11:47 am)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Mon Dec 24, 3:20 pm)
Re: [LAU] Pro Audio? OT rant., Brent Busby, (Mon Dec 24, 4:46 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Mon Dec 24, 9:12 am)
Re: [LAU] Pro Audio? OT rant., Florian Paul Schmidt, (Mon Dec 24, 9:45 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 12:36 pm)
Re: [LAU] Pro Audio? OT rant., Jeremy Jongepier, (Tue Dec 25, 1:24 pm)
Re: [LAU] Pro Audio? OT rant., Florian Paul Schmidt, (Tue Dec 25, 1:42 pm)
Re: [LAU] Pro Audio? OT rant., Chris Bannister, (Fri Dec 28, 2:35 am)
Re: [LAU] Pro Audio? OT rant., Florian Paul Schmidt, (Fri Dec 28, 10:31 am)
Re: [LAU] Pro Audio? OT rant., Chris Bannister, (Fri Dec 28, 3:05 pm)
Re: [LAU] Pro Audio? OT rant., Jörn Nettingsmeier, (Sat Dec 29, 6:22 pm)
Re: [LAU] Pro Audio? OT rant., Arnold Krille, (Sat Dec 29, 9:18 pm)
Re: [LAU] Pro Audio? OT rant., Florian Paul Schmidt, (Sat Dec 29, 8:54 pm)
Re: [LAU] Pro Audio? OT rant., Jörn Nettingsmeier, (Sat Dec 29, 11:36 pm)
Re: [LAU] Pro Audio? OT rant., Chris Bannister, (Sun Dec 30, 12:08 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sun Dec 30, 2:12 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Sat Dec 29, 6:30 pm)
Re: [LAU] Pro Audio? OT rant., Chris Cannam, (Fri Dec 28, 4:52 pm)
Re: [LAU] Pro Audio? OT rant., Folderol, (Fri Dec 28, 5:31 pm)
Re: [LAU] Pro Audio? OT rant., Chris Cannam, (Fri Dec 28, 11:06 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Fri Dec 28, 10:51 pm)
Re: [LAU] Pro Audio? OT rant., Al Thompson, (Sat Dec 29, 2:03 am)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sat Dec 29, 11:27 am)
Re: [LAU] Pro Audio? OT rant., Al Thompson, (Sat Dec 29, 3:05 pm)
Re: [LAU] Pro Audio? OT rant., Raffaele Morelli, (Fri Dec 28, 11:12 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 2:39 pm)
Re: [LAU] Pro Audio? OT rant., Chris Bannister, (Fri Dec 28, 3:10 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Fri Dec 28, 6:25 am)
Re: [LAU] Pro Audio? OT rant., Jeremy Jongepier, (Fri Dec 28, 1:29 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Fri Dec 28, 2:53 pm)
Re: [LAU] Pro Audio? OT rant., Gene Heskett, (Fri Dec 28, 7:13 am)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Thu Dec 27, 3:10 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Thu Dec 27, 5:20 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Thu Dec 27, 11:31 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 5:25 pm)
Re: [LAU] Pro Audio? OT rant., Neil, (Thu Dec 27, 10:37 pm)
Re: [LAU] Pro Audio? OT rant., Fernando Lopez-Lezcano, (Mon Dec 31, 2:28 am)
Re: [LAU] Pro Audio? OT rant., Neil, (Mon Dec 31, 8:15 pm)
Re: [LAU] Pro Audio? OT rant., Charles Henry, (Mon Dec 31, 8:57 pm)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Wed Jan 2, 8:35 am)
Re: [LAU] Pro Audio? OT rant., Neil, (Mon Dec 31, 9:17 pm)
Re: [LAU] Pro Audio? OT rant., Charles Henry, (Mon Dec 31, 9:39 pm)
Re: [LAU] Pro Audio? OT rant., Tim E. Real, (Mon Dec 31, 10:44 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Tue Jan 1, 5:23 pm)
Re: [LAU] Pro Audio? OT rant., Al Thompson, (Tue Jan 1, 6:37 pm)
Re: [LAU] Pro Audio? OT rant., Gene Heskett, (Tue Jan 1, 7:20 pm)
Re: [LAU] Pro Audio? OT rant., Al Thompson, (Wed Jan 2, 12:26 am)
Re: [LAU] Pro Audio? OT rant., Tim E. Real, (Wed Jan 2, 8:14 am)
Re: [LAU] Pro Audio? OT rant., Al Thompson, (Wed Jan 2, 8:23 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Tue Jan 8, 2:30 pm)
Re: [LAU] Pro Audio? OT rant., Folderol, (Mon Dec 31, 10:02 pm)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Wed Jan 2, 8:43 am)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Fri Dec 28, 2:38 am)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Thu Dec 27, 11:22 pm)
Re: [LAU] Pro Audio? OT rant., Neil, (Fri Dec 28, 4:41 am)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Thu Dec 27, 11:24 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Thu Dec 27, 11:14 pm)
Re: [LAU] Pro Audio? OT rant., Neil, (Thu Dec 27, 11:23 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Thu Dec 27, 11:47 pm)
Re: [LAU] Pro Audio? OT rant., Gene Heskett, (Fri Dec 28, 12:22 am)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Fri Dec 28, 5:30 am)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Fri Dec 28, 12:18 am)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Sat Dec 29, 2:38 am)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sat Dec 29, 11:13 am)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sat Dec 29, 2:48 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sat Dec 29, 7:54 pm)
Re: [LAU] Pro Audio? OT rant., Al Thompson, (Sun Dec 30, 4:19 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sun Dec 30, 4:53 pm)
Re: [LAU] Pro Audio? OT rant., Len Ovens, (Sun Dec 30, 4:57 pm)
[LAU] Live mic and monitoring (was rant.), Len Ovens, (Sat Dec 29, 8:56 pm)
Re: [LAU] Live mic and monitoring (was rant.), Marius Janßen, (Sat Dec 29, 11:26 pm)
Re: [LAU] Live mic and monitoring (was rant.), Roger, (Sun Dec 30, 9:35 am)
Re: [LAU] Live mic and monitoring (was rant.), Thomas Vecchione, (Sun Dec 30, 10:48 am)
Re: [LAU] Live mic and monitoring (was rant.), Jörn Nettingsmeier, (Sat Dec 29, 11:23 pm)
Re: [LAU] Live mic and monitoring (was rant.), Thomas Vecchione, (Sun Dec 30, 10:43 am)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sat Dec 29, 2:55 am)
Re: [LAU] Pro Audio? OT rant., Bob van der Poel, (Sat Dec 29, 3:07 am)
Re: [LAU] Pro Audio? OT rant., Brett McCoy, (Thu Dec 27, 11:36 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Thu Dec 27, 11:07 pm)
Re: [LAU] Pro Audio? OT rant., Al Thompson, (Wed Dec 26, 5:51 am)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Mon Dec 24, 7:17 am)
Re: [LAU] Pro Audio? OT rant., Brent Busby, (Mon Dec 24, 4:38 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 1:57 pm)
Re: [LAU] Pro Audio? OT rant., Jeremy Jongepier, (Tue Dec 25, 1:33 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 2:27 pm)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Tue Dec 25, 2:11 am)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Mon Dec 24, 5:08 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Mon Dec 24, 2:27 pm)
Re: [LAU] Pro Audio? OT rant., SxDx, (Mon Dec 24, 3:25 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 1:27 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Mon Dec 24, 3:40 pm)
Re: [LAU] Pro Audio? OT rant., Ricardus Vincente, (Mon Dec 24, 4:33 pm)
Re: [LAU] Pro Audio? OT rant., Paul Davis, (Mon Dec 24, 3:46 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Mon Dec 24, 4:37 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Mon Dec 24, 5:05 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Mon Dec 24, 4:01 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Mon Dec 24, 3:01 pm)
Re: [LAU] Pro Audio? OT rant., Paul Davis, (Mon Dec 24, 2:48 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 1:10 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Mon Dec 24, 3:05 pm)
Re: [LAU] Pro Audio? OT rant., SxDx, (Mon Dec 24, 8:58 am)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Mon Dec 24, 3:14 am)
Re: [LAU] Pro Audio? OT rant., Ricardus Vincente, (Mon Dec 24, 3:23 am)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sun Dec 23, 10:45 am)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sun Dec 23, 5:30 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sun Dec 23, 9:35 pm)
Re: [LAU] Pro Audio? OT rant., Thomas Vecchione, (Sun Dec 23, 10:05 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sun Dec 23, 10:17 pm)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Sun Dec 23, 10:32 pm)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Sun Dec 23, 10:17 pm)
Re: [LAU] Pro Audio? OT rant., Joe Hartley, (Sun Dec 23, 6:07 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sun Dec 23, 9:01 pm)
Re: [LAU] Pro Audio? OT rant., Gene Heskett, (Sun Dec 23, 7:48 pm)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Sun Dec 23, 10:05 pm)
Re: [LAU] Pro Audio? OT rant., Chris Bannister, (Mon Dec 24, 3:20 am)
Re: [LAU] Pro Audio? OT rant., Fons Adriaensen, (Mon Dec 24, 1:55 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 12:53 pm)
Re: [LAU] Pro Audio? OT rant., Gene Heskett, (Thu Dec 27, 1:05 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Thu Dec 27, 3:17 pm)
Re: [LAU] Pro Audio? OT rant., Gene Heskett, (Mon Dec 24, 4:13 pm)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Mon Dec 24, 3:47 am)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Mon Dec 24, 3:49 am)
Re: [LAU] Pro Audio? OT rant., Monty Montgomery, (Sun Dec 23, 10:01 pm)
Re: [LAU] Pro Audio? OT rant., Paul Davis, (Sat Dec 22, 9:53 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sat Dec 22, 10:05 pm)
Re: [LAU] Pro Audio? OT rant., Ralf Mardorf, (Sat Dec 22, 7:10 pm)