[sdiy] State Variable Filter self oscillation

[Grant Richter]

It is the analogue computer simulation of a damped mechanical system (spring
pendulum?). Probably the first design to move from analogue computer to
electronic music, as it is in every analogue computer text book dating back
to the 30's and 40's.

The biquad is a variant that use a single resistor to set Q, may work better
for oscillating.

> From: <synth at charlielamm.com>
> Date: Tue, 1 Apr 2003 20:09:40 -0800 (PST)
> To: John Blacet <blacet at blacet.com>
> Cc: <synth-diy at dropmix.xs4all.nl>
> Subject: Re: [sdiy] State Variable Filter self oscillation
> 
> How does one define a "classic state variable" filter?  I am curious.....
> 
> --CL
> 
> On Tue, 1 Apr 2003, John Blacet wrote:
> 
>> Has anyone built a classic state variable that can oscillate?
>> 
>> I have a few versions of this filter that get close but do not sustain
>> an oscillation.
>> 
>> Still poking around the breadboard, but any comments?
>> 
>> Regards,
>> --/////--
>> John Blacet
>> Blacet Research
>> http://www.blacet.com
>> 
>> 
> 
>