From: gordie@mcode.amdahl.com (Gordon Freedman)
Newsgroups: rec.audio
Subject: DCC/MD comparisons (was Re: New LP-CD flame material)
Date: 7 Apr 92 01:05:35 GMT
Reply-To: gjf00@duts.ccc.amdahl.com
Organization: Amdahl Corporation, Sunnyvale Ca.

In article <1992Apr6.193457.15311@news.eng.convex.com>, jgardner@convex.com (John B. Gardner) writes:
> 
> Anyway, Kurt (or anybody) have you an opinion on DCC (or MD)?  A recent
> article in SR or Audio indicated that extensive ABX tests with a wide
> variety of source material (and test equipment) found that there was *no*
> reviewer who could indicate any difference what so ever between DCC
> processing and straight-wire.
> 
> This is significant, not only could the (fairly elite) panel not identify
> the processed signal, they could not statistically determine there was any
> difference at all. 
> 
> Comments?
> 
> -- 
>    /\ /_  _    jgardner@convex.com
>    \//_//_/
>    /     /     "Poor is the man whose pleasures depend
>   /    \/       on the permission of another" -Madonna

I have seen a few articles where the reviewers could tell the difference.
There is a rumor that some people have heard some pretty nasty things
coming through DCC that somehow nobody managed to notice before. When
pointed out, though, apparantly these nasties are easily heard. (I think
one thing was some sort of added aliasing tone). This was reported in
some of the Stereophile tidbits towards the front of the magazine in
the past half year.

Some reviewers in a British mag heard differences consistently and 
preferred the non-DCC, this was in a blind test. The magazine (I can't
remember the name) has articles where the reviewers aren't told which
units they are listening to, and make comments about them. Later, the
names of the units are filled into the comments so something like
"The A sounded warmer with a better soundstage ..." becomes
"The Quadia Bytestream sounded warmer with a better ...".

I haven't heard DCC or MD so I have no opinion yet based on experience,
but note these things:

 1) Sony comes right out and says that MD will not have the quality of CD,
    and is not intended to be a competitor of CD or DAT.

 2) DCC's launch has been delayed around 6 months or so, this after
	there was some negative feedback (no pun intended) on demos.

I have also heard that the mechanical properties of DCC are similar to
analog cassette (mechanical properties of the tape/head and drive, not
the actual technology of storing information). This means that DCC tapes
may have a limited lifetime like cassettes, in terms of dropouts and
ability to rerecord on them. DAT tapes, o nthe other hand are pretty 
robust, I have recorded over DAT tapes 10s of times, and they have held
out over repeated plays for at least 6 years (and counting).

And I think there have been articles in SR and Audio in the past that
have indicated that *no* reviewer could tell the difference between
just about anything. Whether the tests were bogus or their reviewers
have 12AX7s in their ears is unknown to me.

-- 
Gordon Freedman: gjf00@duts.ccc.amdahl.com  -> Dis: DAT
The difference between theory and practise in practise is greater than
the difference between theory and practise in theory - someone else's sig
Newsgroups: rec.audio,rec.video.cable-tv