Interesting Paper available on Moog VCF

[Sean Costello]

At 07:16 PM 9/17/96 +0200, you wrote:
>Howdy DIYers,

>If you can find a way to digitally simulate eg the famous Moog VCF
>and implement this in a modern synth (a'la NordLead), its almost
>certain that you can make money out of it...

Judging from the source of the Moog VCF paper (Julius Smith at Stanford),
the digital Moog money would be going to Yamaha.  Yamaha has subsidized work
at Stanford for a long time; first the FM stuff with Chowning, and now the
physical modelling work of Julius Smith and Perry Cook.  My bet is that
there is a "Virtual Moog" in the works at both CCRMA and Yamaha; another one
of Stilson's papers was how to simulate "classic" analog waveforms in the
digital domain. 

>Luckily (for us) it will be quite some time before a digital simulation
>of a VCF can really compete with the real thing ;)

The Moog VCF paper wasn't even concerned with simulating the particular
quirks of the Moog filter; it was simply trying to come up with a digital
simulation of a filter that used four identical one-pole filters that were
cascaded, with feedback going around all four (you know what I mean - I
can't explain it too well due to my lousy technical abilities).  This is as
much a simulation of an ARP 4075, SSM 2040 or CEM 3320 as it is a simulation
of the Moog filter.  

Sean