Tue Jan 4 04:55:22 EST 2011

Tim Stilson PhD Introduction

Looks like he finished his PhD in 2006[1].

His work is mostly not about oversampling and non-linearities, but
about non-oversampled techniques.  ( Though I doubt BLIT and BLEP can
be considered non-oversampled, as they are essentially oversampled
lowpass. )

Anyways, in the section about discretization of continuous filters he
mentions the Delta Operator on page 33, which also appeared in the
book "Finite Difference Equations"[2] I read the first part of
recently.  The idea is to use an integrator/differentiator analogy to
note discrete systems instead of the unit delay as this is more
elegant and more closely resembles the analog case.  This then gives
the difference calculus, a set of rules to manipulate formulas with
deltas, as exposed in [2].

The advantage of this encoding is that it isn't plagued by numerical
issues for highly oversampled systems, i.e. Sigma-Delta modulators.

There should also be a link to automatic differentiation somewhere...
I.e. using memoized / butterfly-style networks instead of
multiplied-out direct formula resembling "convoluted" bell/binomial
shaped coefficients as Tim mentions.

I need to explore other references too..  Goldmine.

Dana Massie: EQ, Harvey Thornburg: NL moog.  Antti Huovilainen: moog
circuit model.

[1] https://ccrma.stanford.edu/~stilti/papers/Welcome.html
[2] isbn://0486672603