AW: [sdiy] Re: Companders

[Ullrich Peter]

>I believe there was a German company that also made compander-based noise
>reduction circuitry. In their system, the audio spectrum was split into
>three different bands. The Bass, Midrange, and Treble were all sent through
>different companding circuits. This was supposed to greatly reduce the
>"pumping" or "breathing" effects like the ones you have described. I never
>did have the chance to use this "tri-band" style of noise reduction, but it
>seemed to be a good idea. Does anyone on the list know about the circuitry
>I'm referring to, but can't remember the name of? If anyone has used it,
>did it work better than DBX?

You mean HighCom from Telefunken! It was used in some tapedecks from EUMIG, 
TELEFUNKEN,... 

I still have some chips lying around and also untested PCBs as I wanted to
switch it in front and after a 8 bit digital delay line to get a better dynamic response
then the theoretical 48dB. But I never finished the project...

The chips name was  U401BR from Telefunken (TFK).
If anyone is interested I could make a scan of the Highcom-Module...

Ciao
Peter

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                   Ing. Peter Ullrich         mailto:ullrich at kapsch.net
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                   Hardware & Software Developer /  Electronic Musician
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