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Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!ihuxi!store2
From: store2@ihuxi.UUCP
Newsgroups: sci.electronics
Subject: Re: 3800 Hz notch filter [will] be used on CD masters
Message-ID: <1597@ihuxi.ATT.COM>
Date: Mon, 22-Jun-87 17:45:21 EDT
Article-I.D.: ihuxi.1597
Posted: Mon Jun 22 17:45:21 1987
Date-Received: Fri, 26-Jun-87 01:51:23 EDT
References: <598@neoucom.UUCP> <67@sdeggo.UUCP>
Sender: store2@ihuxi.ATT.COM
Organization: AT&T Information Systems - Naperville, Illinois
Lines: 25
Keywords: with possible icky results!
Summary: can't remove chip

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.  How much do you want to bet that 
> Radio-Electronics has an article "for experimental and educational purposes"
> on how to do it within a month after they come out?
> 
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.
Even if you never copy a CD, you will have to listen to the CD with a
200 hz notch in it and some people claim you can hear that it is missing.
I don't know.  I was at CES but I didn't see any setup with a CD player
playing a copy protected disc.  I did hear a DAT player.  Very impressive!


					Kit Kimes  
					AT&T--Information Systems Labs
					...ihnp4!iwvae!kimes

"I'm carrying the weight of all the useless junk a modern man accumulates.
I'm a statistic in a system that a civil servant dominates."
	_Running On Ice_ -Billy Joel