Resonance CV can be added to a filter by using an external VCA:
1) Run the output of your -420 into a multiple.
2) One of the multiples is your "main" out.
3) Run the other multiple through a VCA, then back into the second audio
input of the -420.
4) The CV of the VCA will then be resonance CV (and the input attenuator of
the second audio input will also control resonance amount).
The same method could also be used to get voltage-controlled feedback for
an analog or digital delay.
For the amplifier, you'd have to tap into the "wet" reverb and vibrato
lines, and bring them each through a VCA. There would be plenty of room
inside most amps, I would think, to stick two VCA's and (if necessary) the
regulators to run them. Not a trivial mod, however. (I assume that you're
talking about vibrato AMOUNT, as this wouldn't work for vibrato SPEED.)
At 01:52 PM 04/18/2000 -0400, Nathan Hunsicker <
nate@...> wrote:
>Sorry for the mistake, I meant resonance. I was more looking to have
>voltage control over the reverb and vibrato controls on my amp. I thought
>there would be an easy way to create a voltage controlled variable
>resistor.
A VCA with a maximum gain of unity would behave as a voltage-controlled
variable resistor for the signal flowing through the VCA.
Somebody correct me if I'm wrong!
-Doug
ceres@...