[sdiy] Basic Synth Patch? VCO-VCF-VCA

[harrybissell]

Hi Mike

The VCO-VCF-VCA is usually done that way so that any residual
noise (ESP from the VCF) will be attenuated as much as possible when
the notes are off.

You could go with VCO-VCA-VCF and that would allow (or feature)
variable overdrive at the max VCA setting. But if you don't close the
filter to sub-audio, and you have high resonance you will still hear the
VCF
when the notes are off. (if it is self oscillating you will REALLY hear
it !!!)

You could use a second VCA as you mentioned. You could also sum the
"AM" signal with the envelope and get the AM mod you wanted from a
single
VCA.

The standard patch "is" correct in almost every case... but there would
be patches that
you could use with the alt. configuration as well.

My analog synth (for theremin use) does not even HAVE a VCA... it has
LFO-VCO-VCF
 Its expected that when you finish playing you pull away from the volume
antenna...and the
VCF closes to sub-audio. It works great. In this case there are no Env
Generators.

You 'may' find that AM mod of a VCO (like guitar amp 'tremolo') is much
less interesting
or satisfying than FM (vibrato).

H^) harry

sorry I can't use "Synth-God" (supreme position is taken...) but I will
answer to
Synth-Heirophant  or similar superlative  :^P

Michael Boracci wrote:

>  Dear Synth Gods,I need to understand the basic synth patch of
> VCO-VCF-VCA. It seems to me that one more VCA would be needed between
> the VCO and VCF. There has been mention, several times on this list
> about overdriving the Moog filter. How would this be done with VC, if
> a VCA is not used between the oscillator and filter?In addition to the
> basic amplitude control function I would think that since there is an
> FM input on most VCO's, there should be AM as well
> right? http://www.analogue.org/mr/ms20/ Mentions VCO_VCF_VCA as a
> "standard"Mike