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Path: utzoo!linus!philabs!prls!amdimage!steve
From: steve@amdimage.UUCP (Steve eidson)
Newsgroups: net.audio
Subject: Re: Take the CD challenge!
Message-ID: <447@amdimage.UUCP>
Date: Tue, 6-Aug-85 13:22:27 EDT
Article-I.D.: amdimage.447
Posted: Tue Aug  6 13:22:27 1985
Date-Received: Sat, 10-Aug-85 20:30:16 EDT
References: <3339@decwrl.UUCP> <436@petrus.UUCP> <1295@houxm.UUCP> <1029@ulysses.UUCP> <2362@amdcad.UUCP>
Reply-To: steve@amdimage.UUCP (Steve eidson)
Organization: AMDIMAGE, Sunnyvale, CA
Lines: 48
Summary: 

I hate to disagree with a fellow AMD'er and I'm probably opening
Pandora's box, but recently I found that there is an audible
difference in low-end (under $500) players. Now, I'll be the
first one to admit that there probably shouldn't be a difference
and before last week I'd have told anyone saying there was that
they were full of it.

Anyhow, a good friend of mine has been interested in purchasing 
a new player in the past few weeks, and asked me to come along to do
some test listening. So we went to several local shops (no high-end
stores, we weren't interested in how much we could spend), and found 
one that had the two players my friend had taken a shine to (Technics
SL-P2 and Yamaha CD-X2). He had narrowed his choice for drawer
mechanics and programming features. He preferred the Technics at first
because of its styling and programming, but both our minds quickly
changed after an A/B test (through the same pre-amp, amp, & speakers)
using a digital recording of the Nutcracker.

The triangle which was crisp and clear using the Yamaha, almost 
disappeared when played through the Technics. This was not meant 
to be an ad for Yamaha, but there are two new believers in CD
differences.

My suggestion (aside from a double blind A/B test) is to thoroughly
quiz any salesman about the type and number of DACs used as well as
the analog anti-alias filters.  Find out whether the DACs are
14-bit or 16-bit, and if interpolation is used or not. Interpolation 
relaxes the constraints on the analog output filter since the
aliased signals that must be attenuated are at a higher frequency.
Sloppy filter design will ruin any advantage gained by
interpolation. Two DACs are theoretically better than one.

The most unfortunate thing is that most salesmen don't know
what the hell they're talking about. In one of the stores we
went to, a salesman tried to tell that the Yamaha had three lasers
(it does actually) and the player took a vote on the proper
digital code; best two out of three, majority rules. We couldn't
help laughing at him. When we asked for an owner's manual,
he left pretty quickly. 

 Happy shopping.
 ----------
 "...but you've got no arms and no legs,
 what are you going to do, bleed all over me ..."

 Steve Eidson (408) 749-2303
 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!amdimage!steve
 ARPA: amdcad!amdimage!steve@decwrl.ARPA