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From: drm2@mvuxn.att.com (David R Moran)
Newsgroups: rec.audio.high-end
Subject: Re: Chesky's 128x oversampling
Message-ID: <13394@uwm.edu>
Date: 25 Jun 91 12:52:09 GMT
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In article <13355@uwm.edu> jas@proteon.com (John A. Shriver) writes:
>I think the only thing "proprietary" about Chesky's 128X oversampling
>is that they built their own A/D hardawre to do it.  They did this
>over a year ago, before the DCS 900 was available.  Maybe a more
>appropriate term would have been "exclusive", since at that time they
>were producting the only CD's mastered through oversampling A/D's.
>(I have no idea how many bits they are taking per sample.)
>

Where do you get this stuff? The tweak mags, or manufs' lit?

So far as I (or anyone else, I believe) know, Chesky uses the UltraAnalog
(dbx) low-bit A/D, the first of the new generation of linear-phase
A/Ds. It was designed by Bob Adams in 1987; he is now at Analog 
Devices. Crystal in Texas makes the only other such, I think. D/As with 
good phase behavior are now easy; A/Ds are not, not at all. The DAT decks 
with good A/Ds say
inside, on the chip, Asahi, which is the distributor of the Crystal part
in Japan (I think I have this right). Analog Devices is about to come out
with its own (or already has) wonderful A/D, better than anything else,
I hear. Not Philips nor Sony has anything like this; Sony will likely
buy a lot of the Analog Devices part. The UltraAnalog/dbx set is large,
not fully integrated, expensive, and the Japanese above all else want to be
sure of the supply.... Telarc (recently) and Albany are two other labels 
besides Chesky which use the UltraAnalog A/D. Albany's is a custom
bootleg, in fact, I hear. The situation is fluid and
changing as we speak. Perhaps Hauser can enlighten us further or
correct any mistakes I have made. But Chesky did not do their own
design, and all of the tweako bullshit (Wadia, Apogee, et al.) I
believe does not obtain for the field of linear-phase A/D converters....

David Moran