[sdiy] VCF based in CD4007

[labolida]

Hi Yves

The relationship C2 / C1 determines the Q factor (gain in the filter frequency) for the Sallen-Key model. 
Increasing C1 grows the resonance as:

Vo     1
--=--------------------
Vi  2 squareroot(C2/C1)

In the project the relationship was fixed in 0.3 in order to obtain a widely range of  resonance, from a soft response near 6dB/octave to oscillation.
I hope been clear, and don't hesitate to contact me for any doubts.
Regards
Miguel Labolida

De:"Yves Usson" yves.usson at imag.fr

Para:"labolida" labolida at terra.com.br

Cópia:

Data:Wed, 8 Mar 2006 11:11:39 +0100

Assunto:Re: [sdiy] VCF based in CD4007

> Hi
> 
> I have a question concerning your 4007 VCF.
> Why C2 has a different value than that of C1 ?
> I'd expect them to be the same value...
> 
> Cheers
> 
> Le 7 mars 06, à 18:30, labolida a écrit :
> 
> > Hi all
> > Apologise for my English. Enclosed a simply VCF diagram. I hope to be 
> > useful.
> > Sorry I haven't site for post it.
> > Regards
> > 
> -------------------------------------------------
> Yves Usson
> email : yves.usson at yusynth.net
> web site : http://yusynth.net
> 
>