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Re: Re: again about compression

Subject: Re: Re: again about compression
From: Walter Knapp <>
Date: Sat, 06 Apr 2002 12:18:58 -0500
Gianni Pavan wrote:

> >Walt wrote:
> >I take it you managed to find a way around clock syc to get the
> >difference file. When I tried this using the Portadisc via USB to my G4,
> >I got a beat frequency in the difference file that basically made it
> >useless. Did find out the two clocks differed by about 1 cycle every 2.7
> >seconds or so.
> >
> >I should try it again using the Roland and see if the results are the same.
> 
> If I send a digital signal to the Roland UA5 it accepts the incoming rate
> but it resamples to its internal clock. This produces clearly audible beats
> (clearly visible on a wavform display) if your signal is a high frequency
> constant tone.

This is exactly the sort of problem I was describing. I'll have to see
what happens with the UA 30. I know it gives nothing that's audible, but
the difference test is much more sensitive.

This area is one of the problems of digital audio. Unlike the popular
belief digital audio does not guarantee that your signal will be
unchanged. I happen to believe that we got rid of more problems (that
were in analog recording methods) than we gained from digital. Making
digital worth it.

Walt



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