On Mon, 14 Mar 2005 20:49:03 +0200
Jussi Laako <jussi.laako(a)pp.inet.fi> wrote:
Typical newsgroup FUD.
The paper referenced is this one:
http://sjeng.org/ftp/SACD.pdf
by Lipshitz and Vanderkooy, two absolute *GIANTS* in the field of digital
audio theory and practice.
First of all, most of current A/D and D/A converters
are delta sigma
modulators.
Yes, but from what I've heard, with modern delta-simga converters,
the minimum bit width is 4 bits, not one bit.
If you record something at for example 24-bit 192 kHz
(using
typical delta sigma converter),
The A/D converters now use a minimum of 4 bits.
do some editing (in float format)
Ie it gets convertered to PCM.
and
then output the master as PWM for SACD.
They *may* be some advantage here in that you can pay for a very
expensive PCM -> SACD converter at the mastering stage and the
playback system becomes simpler.
However, Sony is pushing SACD as a complete solution for the whole
audio chain. Sony and others are working on SACD multi track recorders
and so on. It is this in particular that Lipshitz and Vanderkooy and
trying to address.
Erik
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Erik de Castro Lopo nospam(a)mega-nerd.com (Yes it's valid)
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