[sdiy] some design questions from a beginner

[bmc at email.arizona.edu]

ok, now, as i begin to design my hardwired synth, i have module layout questions.
so here we go...

is it, in anyone's experience, practical to have a switchable filter system
that switches between a hi and lo pass in series and a hi and lo pass in
parallel, effectively switching between variable band and notch pass filter
systems? i could still have just a hi or lo pass with the twist of a knob,
the advantage is just the variable pass rate. i know that some commercial
synth uses it (well, i'm pretty sure someone talked about it on the list)
but is this pragmatic? does this sound good? that's my real question.

in regards to frequency modulation...i understand this can be done with a
VCO. does this mean that i should have two VCOs in parallel and then one
VCO modulating both of them? should i just have several VCOs in series? aren't
they typically in series anyways? and, if so, doesn't this mean that frequency
modulation is merely an unavoidable (but not negative) consequence of multiple
VCO synthesis? or should my 'program' VCO be at a differnt frequency range
than my 'carrier(s)'? i am seized with confusion, as you can probably tell.


and, finally, do special effects (ring modulation, distortion, AM) go between
the VCF and VCA typically? what are the effects of placing them in other
places? i can't imagine that they'd go between the ADSR and VCA on the gate/trigger
signal, but who knows. 


phew! slowly i will learn (but that makes it that much more satisfying, doesn't
it?) sorry for the post length.


-bc