[sdiy] Filters

[harrybissell]

MS-50 used a diode bridge... same same

H^) harry

Grant Richter wrote:

> on 1/2/04 5:58 PM, Linium at intent at netpratique.fr wrote:
>
> > On Vendredi 2 Janvier 2004 14:50, jbv wrote:
> >>>> Is there a (easy) way to modify this VC-BPF design :
> >>>> http://www.cgs.synth.net/modules/cgs35_syntha_vcf.html
> >>>> to add VC-Q to it ?
> >>>
> >>> Replace the Q pot with a LDR+LED (and 1k resistor parallel to the LDR) ?
> >>
> >> Mmh... I guess there my be a slighly more hi-tech, OTA-based
> >> solution...
>
> That is called a "Sallen-Key" filter. Buchla implemented it using a Vactrol
> for the transconductor. Neil Steiner used diodes as the transconductor. The
> Korg MS-20 implemented it using an OTA.