Interesting Paper available on Moog VCF

Eli Brandt eli at ux3.sp.cs.cmu.edu
Wed Sep 18 19:22:19 CEST 1996


Don Tillman wrote:
> Analog nonlinearities are extremely difficult to implement digitally.
> When you add a digital nonlinearity you create an infinite number of
> harmonics, and these alias around and sound pretty crappy.

Interesting.  My gut feeling is that if the waveshaping function is
"smooth" in some sense, it should produce a band-limited output.  

For example, waveshaping a sinusoid with a Chebychev polynomial will
exactly produce a known band-limited output.  (Of course, it could
still fall over the Nyquist limit.)  But this waveshaping function
isn't band-limited itself.  So what's "smooth"?  It would have to
depend on the specific input function... I have no idea how to deal
with this.

(The list is analog-only?  Maybe this should move to electronica.)

--
   Eli Brandt
   eli+ at cs.cmu.edu



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