Wiardgroup

Hi All
it would appear that this discussion is in danger of foundering on the
perilous rocks of semantic conventions 
=]
(smart ass grin)
in his statements:
"Personally I find state variable filters to be completely boring." 
i believe prof. Richter was refering to the filter circuit exemplified
by the Oberheim SEm or the Serge VCFQ; a series of OTA's feeding
integrators, enclosed in an attenuated feedback loop. (& tapped at
three points to yield hi-pass, band-pass & low-pass outputs). This
topology is what techs who are immersed in the culture of analog
synths call a 'classic' state-variable. It's a convention.

But other topologies can yield multiple 'state' ouputs to the muscian
playing them . An array of sallen-key circuits can be configured to
yield various states (this is a clever trick and a trade secret of
wiard , unless i'm mistaken.)  And to the musician using the filter ,
there are 'states' and they are 'variable' so it looks like a duck and
quacks like a duck.... and so he calls it a 'duck'
To maestro Chang a sate variable is as a state variable does.
To prof. Richter a state variable is the blueprint for whats under the
hood. 
The 'state variable' term is being used in two distinctly different
contexts.

ok....
now that THAT little semantic tangle is sorted out, let's hurry up and
finalize an exhaustive definition of 'warm'... 
so that they can finally turn off that annoying Analog Heaven server
};'>
(extra smartass grin + wink, with diabolic provocateur horn attachemnt) 

-doc