[sdiy] My special topics class approved! Whoo hoo!

[Aaron Lanterman]

On Thu, 27 Oct 2005, Charles Bisaillon wrote:

> WoW! I wish I had a class called "Theory and Design of Music 
> Synthesizers". That sounds wicked! The closest I can get to that is 
> "Modern Analog Filter Design" which is a classed intended for telecom 
> option in electrical engineering. It's probably not the kind of filters 
> we wish they were. d:(

They're probably close though... all the VCF's I'm aware of really start 
with a basic standard fixed filter type and then figure out a way to vary 
gains along the chain. I plan to do a lecture or two covering basic fixed 
state variable filters, Sallen-key, and four-pole-with-feedback designs 
before then showing the variable versions. There's many many other filter 
topologies around, most of which appear to have remained unexplored by the 
synth community. In your filter class, you may find some inspiration.

There's one interesting exception to the above observation, now that I 
think about it - the Polyvoks filter. It had no caps, but relies on the 
limited slew of the underlying op amp, and the fact that the slew is 
programmable. It's very very very weird.

> But I will be taking it as an option anyways d:)

Yay!

- Aaron

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