[sdiy] Ladder filter variations

[Don Tillman]

[Itook the liberty of changing the subject line.]

Magnus, Hairy Harry, Osamu-san, gentlefolks,

If you're interested in variations on the ladder filter, I'll suggest
you go to the patent pdf tool:

   http://www.pat2pdf.org

And take a look at this guy:

  US 6,084,470
  Filter Circuit Capable of Setting Various Filter Characteristics 
  Shiramatsu, Nakamura, Goto
  Kabushiki Kaisha Toshiba
  July 4, 2000

This patent is an insane collection of unusual ladder filters.  

Also check out these:

  US 5,912,587
  Active Filter Stack
  Mihailovits, Beatson
  Mitel Semiconductor
  June 15, 1999

  US 5,225,790
  Tunable Widband Active Filter
  Noguchi, Rinaldis, Esling
  Digital Equipment Corp.
  July 6, 1993

  US 3,983,512
  Current Controlled Electrical Circuits
  Lipscombe
  Feedback Instruments Limited
  September 28, 1976

I'm sure some of these have significant musical potential.

Enjoy!


  -- Don

-- 
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com