MOTM

You don't necessarily "need" VCAs in those places to do FM -- If you jack
one VCO's output into the FM input of the second, then you are doing
frequency modulation! Run that output into a filter, VCA, etc and you are
doing it.

Sure, adding a VCA in between would give you an extra method of changing the
harmonic content dynamically. But if you want to experiment with FM, there's
nothing stopping you.

If you're going for the whole DX7 kind of thing, remember that these VCOs
are not the "through zero" type (extremely few analog VCOs are), meaning
that as the modulating signal goes negative, the output phase of the second
VCO will not "reverse."



-----Original Message-----
From: matutchiso [mailto:hutchshop@...] 
Sent: Tuesday, 03 December, 2002 12:21 PM
To: motm@yahoogroups.com
Subject: [motm] FM Synthesis w/ MOTM

Hey MOTM'ers,

I have a 2 osc system with a few filters, e.g.'s and 1 VCA.  So far 
I haven't done much FM with my modular b/c from what I understand, I 
need a VCA for the modulating signal, and another VCA for the 
carrier.  Since I only have 1 VCA, I've been wondering if there are 
other ways around this, such as sampling some waveforms from my 
VCO's and using the envelopes in my sampler to provide the envelope 
for the modulating signal.  Can this work?  

Does anyone have any experience working this way or have any 
suggestions?

Thanks,
-Matt