[sdiy] 24dB multimode VCF it seems to work!

[Tony Allgood]

>It would surprise me in nobody else on the list has tried a 24dB
multimode VCF before. If so how did it go?

I built two state variables together in series. The Q was voltage
controlled so I just ganged the CVs to both SVF together. It gave me a
nice sound, but I didn't like the self-oscillation at high Q, so I
avoided it by limiting the CV. The outputs were not avaliable
simultaneously, but controlled by two DPDT switches. One for BP and LP
and the other for order. The BP output from the first stage would be fed
into the next input when '4 pole' BP (actually -12dB) was selected.
While the LP output from the first would be used to feed the input when
the 4 pole LP output was selected.

Funnily enough, I am actually trashing this synth that this the filter
is in to build another one. I need the parts, and I don't have room for
two synths in that rack.

Regards,

Tony Allgood  Penrith, Cumbria, England

Oakley Modular Synth and TB3030:
www.techrepairs.freeserve.co.uk/projects.htm
My music: www.mp3.com/taklamakan