Sun Dec 26 02:36:01 EST 2010

State variable filter

I have one breadboarded, but intuition is missing.  

- What is the influence of the 2 integrator feedback coefficient?

- How to prevent small resistors = large opamp loads?  See TAOE[1] p
  279 which advises to keep resistors above 5k.

- What about the open loop gain at a particular frequency?  The time
  constant is set by the RC product, but the gain at a particular
  frequency is not.

- Why does the SVF oscillate?  An ideal one is not supposed to.  Is
  this due to noise or nonlinearities?

[1] isbn://0521370957