[sdiy] How do i make a simple filter resonant ?

[Tony Clark]

> Now, i wanted to do some experiments on my own. Simple RC filters
> seem to work, and an OTA filter straight from the National App notes
> works, too.
> But i want these filters to have resonance so they do not sound that dull.
> What shall i do ? Somewhere i have read to feed back some part of the
> output to the input, but this did not work for me.

   Phase is very important as you'll need to feed back in the same phase 
coming into the filter so it "adds" to the signal coming in.

> Could some of you experts point me in the right diection, perhaps a
> "resonant filter tutorial" somewhere ?

   Might be difficult to find one as us synth geeks are the only people 
(that I'm aware of) that really _want_ a filter to resonate!  Most filter 
design tutorials are going to try to explain how to get perfect flat 
responses.  :(
   Try doing searches for "High Q" filters.

   Anyone else?

   Tony

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