Re: vca?

From Mark Pulver
Sent Mon, Jul 13th 1998, 19:55

jack the stripper (09:15 AM 7/13/98) wrote:

>in a bland continuation of my doepfer saga, i ponder the need for a 
>is a vca totally necessary?   is the output of a mixer/filter/ringmod a 
>sufficient input for a 1202?  or will the sound be insanely quiet like 
>my shitty turntables?

Ummm, dude... Are you ever thinking that you'll want to turn off the sound
from the Doepfer? ie, "gate" it?

The VCA is the module which will allow more signal to pass through it based
on an incoming voltage. You usually will feed the output of the internal
mixer into it, then you go from the VCA to the outboard mixer (your 1202).
The voltage control signal that feeds it is usually an ADSR. When the ADSR
is triggered, it will cause a voltage to appear at it's ouputs, hence the
CV input to the VCA, which then allows the VCA to "open up" and allow the
audio signal to pass.

If you DON'T have a VCA in the system, then you will ALWAYS have sound
coming from the synth. You can use a ring modulator as a VCA, but then you
lose it's use as a ring modulator.

The only reason to NOT have a VCA in a modular system is if you are
designing a system to only process external audio and that audio is gated
before it gets to the Doepfer processing rack. But even then, I'd still
recommend a VCA so that you can re-gate the inbound audio, say to a click
track of drum machine.

Mark Pulver - Home of the "MIDI 2nd Bedroom Featuring the Modular Closet" - Nord Mod: