Re: arsclist Tubes will not die

[James Perrett <jrp@xxxxxxxxxxxxxxx>]

Mike Richter wrote:
> 
> At 04:50 PM 11/13/2002 -0600, Premise Checker wrote:
> > >From the Transhuman news list:
> >
> >---------- Forwarded message ----------
> >Date: Wed, 13 Nov 2002 17:40:20 +0100 (CET)
> >From: Eugen Leitl <eugen@xxxxxxxxx>
> >Reply-To: transhumantech@xxxxxxxxxxxxxxx
> >To: transhumantech@xxxxxxxxxxxxxxx
> >Subject: [>Htech] Re: Tubes will not die (fwd)
> >
> >---------- Forwarded message ----------
> >Date: 13 Nov 2002 08:56:29 -0800
> >From: James Rogers <jamesr@xxxxxxxx>
> >To: fork@xxxxxxxx
> >Subject: Re: Tubes will not die
> >
> >On Tue, 2002-11-12 at 20:07, Jon O. wrote:
> > >
> > > James, this is a JOKE! Perfect CD reproduction?
> > >
> > > How can you say this -- one is bits and one is vibration. They both have
> > > their limitations, but a CD sampling rate is similar to a Mega Pixel
> > > rating on a digital camera. It isn't the thing, but a representation
> > > of the thing. So is a CD. I suppose you can tell me that a 20 mega pixel
> > > digital camera is just like "seeing" photo and 512 bit sample of music on a
> > > CD is equivalent to the live production.
> >
> >
> >The best analog recording formats (which are actually digital when you
> >get down to it) have less signal fidelity than an ordinary Red Book CD.
> >You can record Red Book audio that maintains perfect fidelity WELL below
> >the noise floor and beyond the frequency range of vinyl, so a perfect
> >reproduction of any signal there is trivial.  I would humbly suggest
> >that you study up on sampling theory, signal processing, and other bits
> >of relevant trivia.  You are seem to be demonstrating a classic
> >misunderstanding of how sampling actually works.
> 
> Bah, humbug!
> 
> There is a good deal of truth in the preceding paragraph, but in all it is
> not consistent with the tests I ran many years ago. I will address here
> only the frequency argument.
> 
> It is certainly true in linear analysis - the sort we engineers find
> comfortable - that frequency response on CD-DA is superior to that on
> vinyl. However, we do not hear pure tones and linear analysis does not tell
> us all that we need to know for sound reproduction.
> 
> The issue here is not frequency response per se but response to waveform
> and, with that, to phase error. I have repeatedly run the following simple
> demonstration. Assume that the individual asserts that he can hear nothing
> above 15 KHz.
> 
> 1. Set up two signal generators, both at 8 KHz, one for sine waves, the
> other for square waves
> 
> 2. Using wide-band amplifiers and headphones, challenge the subject to
> adjust one of them - amplitude and frequency - to match the other.
> 

Mike - and any others interested in this subject in depth. There is a
similar but possibly better informed discussion happening on the
pro-audio list at the moment. If you take a look at the recent archives
you'll see how valid this particular test is considered. For more
information on the ProAud list, please send an e-mail containing the
single word "info" (without the quotes) to pro-audio-request@xxxxxxxx

Cheers.

James.
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