[sdiy] Multimode filter topology

[KA4HJH]

At 4:22 PM -0700 8/17/09, David G. Dixon wrote:
>For instance, I can find no reference to the aforementioned allpass mode on
>the web or in any of the books on my shelf; the only reference to it is in
>Grant's webpage given above.  One thing I can do, given that my 4-pole VCF
>has + and - outputs available from every stage, is to test every combination
>I can think of to see if they are any good.

This could save you some time:

http://www.crowncity.net/ratcave/Electro/MIF/mif.html


John Blacet had a similar device (Phasefilter?) years ago that only used
the more "interesting" combos.

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"