From: larry@cs.com (Larry Spence)
Newsgroups: bit.listserv.allmusic
Subject: Re: Kind of Blue / 24k Gold CD's
Summary: warning: very long (hopefully informative)
Date: 7 Jan 93 22:21:33 GMT
Organization: Computer Support Corporation,  Dallas,Texas

In article <ALLMUSIC%93010618451753@AUVM.AMERICAN.EDU> MASUDA@SJSUVM1.BITNET (Mike) writes:
>
>MF uses the original master tape for the mastering of this CD and its
>vinyl counterparts.  Regular releases use a second generation tape
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This isn't necessarily true.  In recent years, record companies have
become more aware of the importance of getting the original analog tapes.
For example, almost _everything_ that Rhino releases or reissues (e.g.,
the Rundgren catalog) is carefully mastered from original (or the best
existing) tapes.  All the current Zappa, Fripp, and many other CDs are
from the best available masters.  Basically, it's a matter of whether the
reissuer takes the time and effort to track down the best tapes.  I've 
never heard of any second generation tapes being used intentionally when 
better tapes were around... anyway, the MFSL discs sound good because (IMHO)
they use the best tape they can find, they set up the analog playback deck 
and electronics carefully and use a decent oversampling A/D converter.  In
other words, what any competent remastering lab _should_ do.

Recall that the MFSL Steely Dan discs were mastered from the same bad
analog tapes as most of the MCA Dan discs.  The original MCA SD pressings
(1985?), made from Roger Nichols' careful digital transfers, allegedly sound
much better than the MFSL CDs.  So it's not like MFSL has some sort of 
magic that guarantees that they have the best source tapes.... and notice
that MFSL never mentioned that some of their CDs were made from second or
third gen tapes!  Only now that MCA is upgrading its discs does MFSL admit
that there was an error.

>Now with the advent of DAT and other
>digital media storage, it is easier to make direct digital clones of the
>master to ship out to CD pressing companies around the world.

I've wondered why all digital masters (e.g., UK vs. US pressings) aren't
identical.  The only thing I can figure is that the local record label
might want to re-EQ things a bit... something about UK and US ears liking
different timbres (?!).  Anyway, my impression is that virtually all CD
masters are made onto videotape (before making the glass CD master), using 
the Sony 1630 digital format.  But for purposes of shipping/storage, a CD 
or DAT would work.  It shouldn't be any great problem to get the correct 
bits sent across the ocean...

>Needless to say, the MFCD is less noisy.

In some cases, the "regular" releases catch up to the MFSL -- e.g., the
US _Dark Side_ is now pressed from the exact same digital master as used
on the Harvest UK CD (which is made from the first-gen analog master).  Of 
course, you may like the EQ on the MFSL disc better (I've heard comments 
about artificially boosted midrange, etc., on some MFSL discs, to make them
sound "better" on typical home systems).  MFSL has admitted that they're
going after the rabid fans who will spend any amount to get their favorite
groups' albums on the "best" CDs.  So a lot of the MFSL/DCC gold CDs are
of "classic rock" faves like Pink Floyd, Moody Blues, Steely Dan, etc.,
where there is a definite market among rich post-yuppies, if no one else.

>Now, when an album is digitally REmastered, it usually means
>that a new master is made from the analog master tape. 

In my experience, _any_ compact disc may and often does say "Digitally
Remastered."  I think the idea is supposed to be that it was mastered
before for vinyl, and now it's been REmastered for CD.  Tons of really
poorly mastered CDs say "Digitally Remastered."  It's meaningless.

>Now about the 20-bit Sony mastering thingymabob, I really don't know if
>that will make so much of a difference in the sound; the resolution
>will definitely be better than conventional 16-bit @ 44.1KHz, 

In a mathematical sense, sure, there's more bits in the intermediate
mastering stages.  But the final product _must_ have 16 bits, or your
player can't play it! %)  So all it is is an oversampling technique,
to minimize the error at _very low program levels_.  Again, you may
like the EQ better on the 20-bit discs, or they may have tracked down
the right analog tapes, but "20-bit technology" by itself is no guaran-
tee of quality.  Many releases on labels like Chessky, Chandos, Sony,
etc., are mastered beautifully, without the ripoff price (yeah, all
that gold adds to the cost, uh huh... how many milligrams?).

>On Au vs Al, I think Au is a better medium for digital.  It lasts
>longer, 

Under MFSL test conditions, maybe.  As I remember it, their test cycles
the discs from below-freezing to hot-dashboard temperatures and back over
and over under high humidity.  Any even under those circumstances, only
the worst of the "normal" CDs develop uncorrectable errors.  Remember,
even a gold CD has dozens to hundreds of low-level (i.e., correctable)
errors per _second_.  The CD format was designed to expect and correct
many errors (e.g., pinholes) as a matter of routine.

Someone over in rec.audio on usenet has a CD they leave outdoors on a 
peg in direct sunlight.  Once a year, he washes the bird droppings off
and plays the disc, with no problems.  I'm not kidding, it's a normal
$15 CD, aluminum.  Almost every "CD rot" case that I've seen has been
the result of a manufacturing defect (e.g., corrosive inks), as opposed
to an inherent problem in using aluminum.

>is more malleable/ductile, 

If you remove your CD from its jewel box correctly, this should never be
an issue.  The fact that so many people yank their CDs out by pulling up
on the outer edges alone, without ruining the discs, should tell you some-
thing.

>and is resistant to oxidation.

This one has been going around for a while.  It turns out that it's nearly
impossible to keep aluminum from _instantly_ oxidizing, when the CD is 
pressed.  But it's not a problem, because the oxide that is formed is
very shiny, and highly resistant to further corrosion.  I accidentally
destroyed the lacquer coating on a Sonic Youth CD recently, leaving the
bare aluminum exposed to the air, and so far there are no signs of any
corrosion, change in reflectivity, or sound quality.  The only thing I'm
concerned about is that the bare aluminum has no protection against small
scratches, which would probably ruin it now.  It's also very vulnerable
to pollution, like oxides of nitrogen -- in normal cases, this would only
be a problem at the very edge of CDs where the metalization goes all the
way out to the very edge.  You may have noticed that most recent CDs tend 
to leave a mm or so of blank clear plastic at the outer edges, to avoid 
problems with edge sealing.  I can imagine releases like Godflesh _Pure_
or Foetus _Sink_ (both over 79 minutes) might eventually have problems,
but that's only paranoid speculation. %)

-- 
Larry Spence
larry@cs.com
uunet!csccat!larry 
Newsgroups: bit.listserv.allmusic