From: hera!gfl@uunet.UU.NET (22402-lenahan)
Newsgroups: rec.audio.high-end
Subject: Re: Transports, converters and all that stuff.....
Date: Mon, 5 Oct 92 13:29:41 GMT
Organization: Bellcore, Livingston, NJ
NNTP-Posting-Host: 129.89.7.4
Summary: a WAG on the origin of differences ...
Originator: tjk@csd4.csd.uwm.edu

colling@math.washington.edu (David Collingwood) writes:
> 
> I am considering two options to upgrade my cd player and would 
> welcome comments and suggestions. Current equipment: B&W 801 series 3,
> Levinson 27.5 amp, Bryston .5B preamp, CAL Icon II cd player.
> 
> I recently home auditioned the Proceed PCD3 (cd player) vs the Proceed 
> PDP3 (processor) + Icon II. After hours of comparing and blindfold
> testing (which drove my wife crazy) I discovered the following: With
> one exception (I'll get to that in a minute) the Icon+proceed processor
> was a clear winner. The combo was more musical than the cdplayer alone.
> Instruments and voices were consistantly better seperated out in space.
> In addition, the combo smoothed out a slight forwardness (brightness)
> in the mid treble that I noticed in the player. These comments applied
> to jazz, chamber music, pop, folk, vocals. The exception was big orchestral
> music, where the player clearly conveyed a better sense of size. The difference
> in the width of soundstage for Orchestral music was significantly
> better on the player vs. the Icon+processor. So, here are some
> questions and I welcome any and all comments:
> 
> 1. Would the quality of cd reproduction of a large complex orchestral work
> depend more heavily on the transport A/D converter than (say)
> something "small" like Sara K's Chesky disc? (ie are my listening
> conclusions imagined or real?)

The source material does not affect the quality of playback.  Period.
Of course, the effects of, say, soundstage width will me more
evident of orchestral than on chamber music (or rock).
> 
I feel that there are two possible causes to what you
heard, and maybe you can extrapolate from these what
to do.

1. Madrigal has stated that they use similar power supply
stuff in the PCD and PCP.  The added mechanicals and
electronics in the PCD place a heavier strain on this,
and add noise to boot.  This affects both the A=>D chip
and the analog stage performance.

2. Jitter on the digital link appears to affect
sound quality.   While in theory, a buffer in the
OSDF chip eliminates this, the impression remains
that well-clocked transport => processor signals
result in better sound.  I've directly experienced
this by plugging and unplugging the timing link
on the linn systems, and by substituting better
specced clock recovery chips in my own home-made
processor (whihc is far from perfect).

I suspect you are hearing a combination of these
two.  Of course, this means that a well-clocked
processor will be more immune to the "sound"
of a transport, and vice-versa.

The power supply problem could be easily fixed,
but the chip regulators (68XX and 3X7 chips)
have poor high frequency gain, and thus reject
digital and broadband noise very poorly.  As
long as audio companies use these off-the-shelf
solutions, power supply problems will remain.

<<rave off>>

I hear the PCP is pretty good, but have not
heard the "III" revision.  Just don't swallow
too much of the common wisdom spouted by
pseudo-technical sales/marketing folks.

Grant