Lowpass with resonance

Algorithm development and general DSP issues

Moderator: frank

donstavely
Posts: 53
Joined: Thu Jan 07, 2010 2:29 pm
Location: Windsor, Colorado

Figuring out filters

Post by donstavely »

I haven't tried to understand your specific project, but I have a general suggestion that has worked extremely well for me so far.

My project uses sweepable 2nd order and 4th order SV filters. I use LTspice to simulate them in the analog domain, using generic op amp integrators. Then I code it directly for the FV-1. The integrators are the state variables, and become the FV-1 registers that get added to each pass.

For my frequencies (<3KHz) the results are dead nuts on. Very productive and satisfying.

You can download LTspice for free at:
www.linear.com/designtools/software/ltspice.jsp

Don
Don Stavely
seancostello
Posts: 74
Joined: Mon Sep 11, 2006 10:04 pm

Post by seancostello »

I was just quiet because I have been working on other tasks. I haven't worked on the FV-1 in a few months. I'm not into that Zen thing anyway. A former coworker put it best: "I don't want you to teach me how to fish. I just want a fish."

I do think that a Moog style cascade should be doable. I haven't done it, though. I remember that the Stilson paper used one pole, one zero filters, with the zeros fixed at z=-0.3.

Sean
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