Good, simple filter cct required

[Matthew S. Padden]

Hi..

	I'm trying to get hold of a simple bandpass or lowpass VCF, as a circuit 
that can be built by first year undergrads. No specialist ICs, just opamps. 
I've breadboarded the filter cct at the top of p278 of Horowitz+Hill, and 
it sounds good, but no voltage control. I could add OTAs, but I wonder if 
anyone has alternatives? No more than six opamps, if possible.

Thanks in advance
--
Matthew S. Padden
Computer Music Research Group
Room M5/14
Music Dept.
Huddersfield University
Queensgate
Huddersfield
England HD1 3DH
p: +44 1484 422288 x2402
f: +44 1484 472656
e: mattp at mindless.com
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