ETI 4600

[Ken Stone]

>The VCF uses a switch cap method for voltage control, in case you're
>wondering. The author also states that his filter design is patented! Doesn't a
>patent only last for ~20 years?

The patents have long since expired, according to the creator's (now
defunct?) web page. He also mentioned his prototype was stolen.

This filter (the 24db LP version) is my favorite filter. I like it better
than either of my roland filters. A number of points that are stressed in
the article (such as only using SCL Solid State Scientific chips) are no
longer valid. Pretty much all cmos is now fast enough to work.

Ken
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                Ken Stone  sasami at blaze.net.au
                   ** Catgirl Paradise **
               <http://www.anime.net/~kens/>
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             <http://www.blaze.net.au/~sasami/>
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