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From: tdn@cmu-cs-spice.ARPA (Thomas Newton)
Newsgroups: net.audio
Subject: Re: cd players
Message-ID: <425@cmu-cs-spice.ARPA>
Date: Mon, 12-Aug-85 03:06:36 EDT
Article-I.D.: cmu-cs-s.425
Posted: Mon Aug 12 03:06:36 1985
Date-Received: Wed, 14-Aug-85 01:15:08 EDT
Organization: Carnegie-Mellon University, CS/RI
Lines: 43

> I've been told by a salesperson that the Sony portable Cd player does not
> produce as good a sound as some of the inexpensive <$300 non-portable units.
> The reason given was that the Sony only has one laser and the non-portable
> units have two.  Is there any truth to this?  Could this have something to
> do with error-correction? I was under the impression that the Sony portable
> had this feature.

The Sony D-5's frequency response is 20-20,000 Hz at +1, -3 dB, as opposed to
the +0.5, -0.5 dB response found on the Radio Shack and larger Sony players.
The "reason" that the salesperson gave you for the difference sounds like a
lot of BS.  I'd recommend double-checking any advice you get in the future.

According to the June 1985 Consumer Reports:

       The D-5 wasn't as outstanding as the other players in a few
     respects, but the only audible consequence was a very subtle
     dulling in the extreme high-frequency range.  The sound quality
     was still top-notch.
       The D-5 was somewhat less tolerant of dirty or damaged discs
     than most of the players we tested, and its scan function was
     slower.  But it was fast at locating tracks, and it had an
     unparalleled immunity to bumps.  We could turn it upside down
     and shake it while it was playing, with no audible effect.  We
     think it would perform well while being carried in its battery
     pack.  (But jogging with it might be too much for the laser
     mechanism to handle.)

Specifications from the advertising brochure for the D-5:

     Error Correction:  Sony Super Strategy Cross Interleave Reed Solomon Code
     D-A Conversion  :  16-bit linear
     Freq. Response  :  20-20,000 Hz, +1,-3 dB
     Harmonic Dist.  :  Less than 0.008%
     Dynamic Range   :  More than 90 dB
     Signal-to-Noise :  More than 85 dB
     Channel Sep.    :  More than 85 dB
     Wow and Flutter :  Below measurable limit

I have no connection with Sony, other than as an occasional consumer of
their products.

                                        -- Thomas.Newton
                                           Thomas.Newton@cmu-cs-spice.ARPA