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Path: utzoo!linus!decvax!tektronix!kimr
From: kimr@tektronix.UUCP (Kim Rochat)
Newsgroups: net.audio
Subject: Are all DADs alike?
Message-ID: <1243@tektronix.UUCP>
Date: Fri, 29-Jul-83 11:33:47 EDT
Article-I.D.: tektroni.1243
Posted: Fri Jul 29 11:33:47 1983
Date-Received: Fri, 29-Jul-83 15:23:20 EDT
Organization: Tektronix, Beaverton OR
Lines: 24

In the July "High Fidelity" and the August "Audio" there are test reports
on  4 digital disk players.  Both reviewers had gotten the Philips test disk
which has square wave and impulse tests.  All fours reviews published 
oscilloscope photographs of the 1 Khz square waves and impulse tests.  The 2
players reviewed in Audio demonstrated a large amount of ringing on
the tops of the square waves and after the impulse.  (I was vastly amused 
because the 2 DAD reviews were separated by a review of a B&O cartridge whose 
1 Khz square wave response was vastly superior to either of the DADs).  The 2
units reviewed in High Fidelity showed much better square wave performance 
(of course one of them was the Philips/Magnavox player, explaining what the 
tests were doing on the disk).  Also, one unit in each magazine showed 
inverted phase on the impulse test.  Audio also measured 2Khz/20Khz phase 
shift at 180 degrees for one unit.

My question to all you digital-philes is "Are you going to pay any attention
to these test results?"  Presumably, all digital players) sound alike
(read perfect) and you're supposed to choose one on the feature/price ratio. 
Are you going to buy the one that rings less and has correct phase and minimal 
phase shift?  Are you going to audition the competing units and decide which 
one "sounds" best?

                                       Good listening,
                                       Kim Rochat
                                       tektronix!kimr