jas@proteon.com (John A. Shriver) (06/24/91)
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.)
With the availability of the DCS 900 (and the Meridian 607), anyone in
the digital audio field can get the benefits of high-quality
oversampled A/D. We can only hope that record producers will admit
that the present analog filtered non-oversampled A/D's are not audibly
perfect, and that they should replace them with this new generation
technology for future recordings. (Unfortunately, the sad reality is
probably that half of them haven't even replaced their anti-aliasing
filters with the improved Apogee ones! Moreover, most studios already
broke the bank going digital, and may well not have the bucks to
replace their Sony A/D's. It's sad that mastering technology is so
far behind the reproducing technoliogy!)
The superiority of the DCS 900 is quite audible. The Mercury CD's are
mastered with it, and I think everyone agrees that they are very close
in quality to the original LP's. I have compared the Dvorak Cello
Concerto Mercury CD to an earlier (UK-only) Philips CD that was not
mastered through the DCS 900, and the differences are glaring. (Both
CD's were mastered from the same 35mm mag-film master.)
(As for that clipping, maybe someone should read that CD with the
CD-ROM player on their workstation and see if the data really is
clipped.)
{There are no blow-dried marketeers at Chesky. Just the wild & crazy
Chesky brothers. I can't comment on the sound of their CD's, but I
love their LP's!}konar@lennon.SRC.Honeywell.COM (Mithat F Konar) (06/25/91)
In article <13355@uwm.edu> jas@proteon.com (John A. Shriver) writes: >...........Unfortunately, the sad reality is >probably that half of [the recording studios] haven't even replaced their >anti-aliasing filters with the improved Apogee ones! Be a bit more careful before hopping onto that bandwagon! There are many who feel that in solving one problem, Apogee created others that are worse than the original problems they were trying to solve. My gut feel (I've never actually run any tests on any pro digital gear) is that the easiest and best way to improve the sound of many pro digital recorders would be to simply get those wretched NE5532 dual ops or NE5534 singles out of the signal path. Replacement with TL07x (yup, that's right), AD711/712/746 or 845, or Motorola MC3408x series would probably work wonders. For some reason I simply cannot phathom, lots of engineers think the 5532 is well suited to audio amplification. I know it was designed for that purpose, but it's really not very good. In the case of a boom-box, it probably would not be a limiting factor on sound quality. But in a demanding applications, it certainly is. -Mithat Konar
drm2@mvuxn.att.com (David R Moran) (06/25/91)
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