Xref: utzoo rec.audio:21700 sci.electronics:12217
Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!microsoft!gordonl
From: gordonl@microsoft.UUCP (Gordon LETWIN)
Newsgroups: rec.audio,sci.electronics
Subject: Re: My CD player is running slow! (!)
Summary: Pitch shifting is easy
Message-ID: <55024@microsoft.UUCP>
Date: 4 Jun 90 14:49:28 GMT
References: <1990Jun2.182334.21396@athena.mit.edu> <6378.26693284@umiami.miami.edu>
Organization: Microsoft Corp., Redmond WA
Lines: 20

In article <6378.26693284@umiami.miami.edu>, chuck@umiami.miami.edu writes:
> 
> There is no way in the world that the CD player would play "slow" or "flat"
> because of the nature of the beast.  ...
> ...Pitch-shifting in the 
> digital domain is a fairly ugly computational process, usually handled by
> high-speed DSP chips.  

This is wrong.  Pitch shifting is easy.  My first CD player was an
inexpensive one and it had a pitch adjustment control on it.  It's my
guess that you can pitch shift just by changing the rate at which you
feed samples to the DtoA convertor.  CD players already have circuitry
to adjust the rotation rate to keep the convertor FIFO happy, so I expect
that if you just change your sample clocking rate the slight change of
the disc rotation rate would occur automatically.

Regardless of how it was done, my old unit, which I paid $400 for maybe
5 years ago did it, so it's not a big deal.

	Gordon Letwin