Happiness is an SSM2040 VCF...

[Matthew S. Padden]

Hi..

	I finally finished soldering and switched on my first module last night, a 
Digisound 80-7 VCSVF- it worked first time! I took _no_ chances when 
installing the SSM2040 chip; quadruple-checks of the power rails and pins, and 
hold onto an earth strap like grim death. I am a happy man (I even recorded 
the first squeaks to DAT for posterity). :) Tonight I should finish its twin, 
so stereo filter silliness should ensue shortly thereafter. 

	One thing I noticed soon after power-up though is the range of the resonance 
control. It _does_ increase Q, but not by very much. The construction notes do 
say that self-oscillation is not attainable with the design (and that the Q 
control voltage should not exceed 10V), but I was expecting a bit more 
peakiness than I'm hearing. I'll check voltages et al tomight. Still, I wonder 
if anyone has modified a DG 80-7 to get self-oscillation with maximum Q? Is it 
simply a case of increasing the gain on the resonance control summing amp 
(taking account of the 10V limit)?

Any advice appreciated
--
Matthew S. Padden
Computer Music Research Group
Room M2/08, 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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"The masses are asses and need Tonto's glasses!" (Mark Mothersbaugh)
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