Wiardgroup

Hi James
--- In wiardgroup@yahoogroups.com, fred fain <esoterrafirma@...> wrote:
> What about the moogerfooger lowpass filter? 
>It has cv controll of resonance.

it's certainly worth a try

> Would you explain the homemade resonance cv patch in depth?

you need 1 VCA (one with an audio input attenuator is preferable) , 1
VCF (ostensibly sans resonance), and 2 SEPARATE jack mults with a
minimum of 3 jacks each


mult1 -> VCF audio in
VCF audio out -> mult2
mult2 -> VCA audio in
VCA audio out -> mult1
patch audiosignal input into mult 1
the output is at mult2

-The VCA CV becomes the resonance CV
-The VCA audio input usually needs to be dialed down to a very low level
-If the VCF already has a resonance knob, turn it down ALL the way (or
don't...if you're an untrammelled squeal fan!)
-it may be necessary to insert an inverter in the feedback path. This
depends on how the VCF and VCA were designed

there is an urban legend (probably apocryphal) that someone scoffed at
a Buchla 200 system in front of Don by ridiculing it's lack of a
resonance control. The story goes that Buchla indulgently explained
that resonance was merely the addition of an external feedback path
around a voltage controlled integrator function (aka a VCF)  and was,
therefore, a PATCH, not an on-board feature of a filter and that the
200 provided the power to implement resonance schemes of different
types which could be designed by the synthesist in accordance with
their needs, rather than one scheme hardwired-in by a dictatorial
designer.

(Mr. Tcherepninwas was obviously listening!)
;'>

cheers
-doc