Conference cookie::notes$archive:cd_v1

    I have Sony's newest brochure that covers their main line of
    CD players (excluding portables and the ES series).  I see no mention
    of dual converters.  Here is what the brochure says is different:
    
    	"...incorporating upgraded internal technology such as a
    	Cerasin (TM) based linear motor, envelope error detection
    	and a convenient timer switch."
    
    The "envelope error detection" is described as follows:
    
    	"This unique error detection system automatically 'freezes'
    	the movement of the laser pickup when no RF tracking signal
    	is present.  This provides faster recovery from tracking
    	errors and more uniform performance."
    
    What is truly baffling is that there is a new model, the CDP-203,
    that seems to be superior to the 302II, in that while it lacks
    the linear motor (thus not having the 302s lightning-fast access
    times) and the timer switch, includes direct access to tracks from
    the front panel, 20-track programming (vs 16 for the 302),
    shuffle play and auto-space.  The remotes appear similar except
    the one for the 203 also has a shuffle-play button.  Specs are
    identical (as much as are listed in the brochure), except that
    the 302 has 2db more channel separation. (95 vs 93dB - whoopee!)
    
    If the 302II really does have more inside, why don't they say so?
    
    				Steve

Here's what I got from 363.0:

>  Sony has solved some more problems with their new fourth (fifth?, I've
>  lost count) generation machines.  The Mark II series of the 302 on up
>  players will finally have dual digital to analogue converters for zero
>  phase shift (in the player anyway, recorders are a whole different story).
>  The new transport has an anti-resonant ceramic material in it to attenuate
>  vibrations that cause errors (experimenters: try Sorbathane).  Also, Len
>  hinted at the use of opto-couplers.  These will help reduce the amount of
>  high frequency noise in the analog output circuitry - very much needed...

Later on in the note there's some reference to the new SONY's ability to track 
disks with defects by shutting down...but it's not clear if this ability was 
limited to the 302II only or was a carryover from the 302.

P.S.
I was curious about the 2 year extended warrenty so I called the SONY 800 
number.  All is well, it's still available (I was worried that because the 302 
was an older model now the "perks" might not be in effect).

    Er, ah, well I've learned my lesson from believing anything Len
    Feldman has to say.  I got the real story at the CES show.
    
    Only the top two ES players have dual DACs (650ESD, 620ES (?)).
    The Ceresin is the stuff I was talking about as was the new servo
    programming.  I'm not sure how far down the line Sony uses opto
    couplers, but they are also in the top two.  Next year the better
    technology will migrate further down the line.
    
    Cerisin is an advance.  Using a disk damper really does work, being
    slightly audible.  Mod Squad has one, Phoenix is comming out with
    a ceramic one from Japan, and Monster Cable is comming out with
    one.  Just sticking another CD on top works almost as well.
    
    I saw some other good CD players at the show.  The new 16-bit
    Magnavoxen were there (as was Mission's mod of it), and JVC had
    a machine with dual oversampled DACs.
    
    Mark

>   Only the top two ES players have dual DACs (650ESD, 620ES (?)).

    This means that, to me, the difference between the 302 and 302II has 
    decreased significantly (of course, I'm assuming that two DAC's really 
    would be much better than one).  Which means the "deal" from Sound 
    Playground may be quite GOOD!!!
    
>   The Ceresin is the stuff I was talking about as was the new servo
>   programming.  
    
    I don't know if Ceresin is only something in the 302II or not.  I know 
    that Digital Audio showed a picture of the drive in the 102 (supposedly 
    the same as the 302).  This was a linear motor too.  Maybe Ceresin is a 
    better version of the linear motor (making it slightly better than what 
    was used in the 302???).
    
    What's servo programming?
    
>   Cerisin is an advance.  Using a disk damper really does work, being
>   slightly audible.  Mod Squad has one, Phoenix is comming out with
>   a ceramic one from Japan, and Monster Cable is comming out with
>   one.  Just sticking another CD on top works almost as well.
    
    What does "really does work" mean.  What's this thing do anyway?

    Dick

    The Cerasin (not Cerisin or Ceresin) in the motor is new to the
    302II and 203.  It should make the player somewhat more immune to
    mistracking because of vibration.  I doubt it makes a difference
    in the sound quality.  Cerasin is a material, not a type of motor.
    Otherwise, the motor in the 302II is the same as that in the 302
    and 102.
    
    As to whether two DACs are really better, that's a matter of opinion.
    I doubt you'd be able to tell the difference on music.  However
    if you play a lot of mono test tones, perhaps you should care....
    
    I don't see any obvious improvement in the 302II that makes it worth
    say $30 more than the 302.
    					Steve

Where'd the $30 come from?  I thought the list prices were $550 for both the 
302 and 302II.  The prices I mentioned in my notes were what I saw.  Those 
were $445 (O'Coin's) and $499 (Leachmere) for the 302II; and $328.88 for the 
302 (Sound Playground).  Those are much more than $30 differences.

    The $30 is what I think the improvements are worth.
    	Steve

    Ok, the Ceresin is in the mounting plate that the motor and laser
    drives mount on.  It (and CD dampers) reduce the vibrations that
    make life hard for lasers trying to focus in on micron details using
    very short focal length optics.  By dampers working, I mean that
    several people AB'd the disk damper and its absence and CD sounded
    better with.
    
    One thing the Differential mumble servo circuitry will do that the
    old wouldn't is track a 2mm defect, where the old would go nuts
    at even 1mm.

To make any audible difference whatsoever, the disk damper would have to
prevent sample dropout errors--cases where the laser absolutely cannot read
a sample and all of the CRC and redundancy information has failed to correct
the read error.  When this happens, the player does a linear interpolation
between the last good sample and the next good sample to determine the sound
level.  If this sort of error occurs a lot, and is corrected by the disk
damper, then you would get an audible difference if you AB'd players with and
without the damper.

I'd be pretty surprised if this in fact was the case.  Was the experiment in
.8 conducted under double-blind conditions?  If not, I find it pretty suspect.

--PSW

    No, it wasn't done in double blind/deaf conditions.
    
    There are other possible explanations for audible difference:
    
    	There is less laser, focus, and motor servo action resulting
    				in less:
    
    	1.  Power supply modulation.
    	2.  RFI generation.
    
    I could only hear a slight difference.  The other listener heard
    none.  People with better ears claimed they could hear the difference
    between using just a second disk and using a damper.  The use of
    these dampers is a fairly widespread phenomanon.  HFN&RR experimented
    with them a long time ago.

    Re: .9   Lets not start a double blind test war here.  I think it
    is agreed that double blind testing is as full of holes as most A/B 
    tests and long term listening. Its just that all the ___ holes are
    different.   ;^)
    
    Walt