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Posting-Version: version B 2.10.2 9/18/84; site spar.UUCP
Path: utzoo!linus!decvax!decwrl!spar!malcolm
From: malcolm@spar.UUCP (Malcolm Slaney)
Newsgroups: net.audio
Subject: Re: one real CD interpolation filter
Message-ID: <496@spar.UUCP>
Date: Sun, 1-Sep-85 16:59:09 EDT
Article-I.D.: spar.496
Posted: Sun Sep  1 16:59:09 1985
Date-Received: Mon, 2-Sep-85 09:17:31 EDT
References: <519@amdimage.UUCP>
Reply-To: malcolm@spar.UUCP (Malcolm Slaney)
Distribution: net
Organization: Schlumberger Palo Alto Research, CA
Lines: 16
Summary: Dithering

In article <519@amdimage.UUCP> steve@amdimage.UUCP (Steve eidson) writes:
>Then, there's a trick that Philips uses. They 
>apply a noise shaping filter (no details provided) to the
>interpolator output. The noise shaping filter reduces the in-band
>(0-20kHz) noise at the expense of increased out-of-band noise.
>The article claims that this reduces the audible noise by another
>7 dB thus making the interpolated system of comparible performance
>to the 16-bit system.
I puzzled over this for a while after I read it and decided that they
must be doing dithering.  Revox published a white paper on their CD
player and described the technique.  I don't remember whether the 
SNR improvement is correct.

Cheers.

							Malcolm