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From: rbl@nitrex.UUCP
Newsgroups: sci.electronics
Subject: Re: 3800 Hz notch filter [will] be used on CD masters
Message-ID: <488@nitrex.UUCP>
Date: Mon, 13-Jul-87 16:57:32 EDT
Article-I.D.: nitrex.488
Posted: Mon Jul 13 16:57:32 1987
Date-Received: Thu, 16-Jul-87 01:07:25 EDT
References: <598@neoucom.UUCP> <67@sdeggo.UUCP> <1597@ihuxi.ATT.COM> <626@gec-mi-at.co.uk>
Reply-To: rbl@nitrex.UUCP ( Dr. Robin Lake )
Organization: The Standard Oil Co., Cleveland
Lines: 22

In article <626@gec-mi-at.co.uk> adam@gec-mi-at.co.uk (Adam Quantrill) writes:
>In article <1597@ihuxi.ATT.COM> store2@ihuxi.ATT.COM (Kit Kimes) writes:
><In article <67@sdeggo.UUCP>, dave@sdeggo.UUCP (David L. Smith) writes:
><> 
><> Instead of messing about with the audio signal, why not just reach in with
><> a soldering iron and clippers and tweak the chip out of the circuit, or
><> make it think that it always has some noise there with a little 3800 HZ
><> oscillator tied to its input.  [..]
><> 
><Sorry, but the protection circuit will be buried deep in one of the LSI's.
><There will be no way to remove it and even if you could, the notch will
><still be there on the source CD.  That is what has everyone so up in arms.
>
>How about frequency-shifting the signal so that the notch is now at 3805Hz?
>A .2% speedup isn't subjectively noticeable.
>       -Adam.
>
>/* If at first it don't compile, kludge, kludge again.*/


How about doubling/halving both the CD and the DAT speeds?
	- rob