Sun Jul 26 14:58:36 EDT 2015

Generating sound-producing ciruits

( Raw except from an email conversation. )

There is something "unnatural" about digitial signal processing.  This
is somehwat related to the idea of "digital synths sound worse than
analog", but I suspect there is a way to make this idea more precise.

If you think about generating random circuits with analog networks
vs. digital processing by just hooking up a bunch of primitive
building blocks, the former would produce a different quality of
sounds than the latter because of a different structural bias.  It has
something to do with the difference between the model of impedance
networks with the current/voltage interplay (force/momentum in
classical mechanics) as opposed to just working with iterative number
systems.  This is very vague I realize but there is something about
physical systems that you don't find naturally when just tossing
numbers around.  Otoh, it's not realistic to just keep building bigger
analog synths :)

Using simulation to explore this creates just enough bias where you
can get into that physical world without leaving the number world, but
it would allow exploring things that are only possible with digital

What I wonder is if it is possible to modify a SPICE engine in such a
way to create some of this bias, while keeping it focused on being
practical and real time.  Not simulating any existing circuits in
particular, but creating a set of primitives that when tossed around
would give a less digital feel.

I.e. suppose the primitives are engineered to not lead to bad
conditioning in the linearized network matrices, i.e. make them less
stiff.  This would allow the simulations to converge faster.  One
would not need to work with diodes and transistors together with
linear elements, but invent new primitives that keep the analog feel,
but are easier to simulate due to better convergence properties.