3080 VCA question

[jhaible]

> "Sometimes it helps to swap the function of the signal input and the
> Iabc input of the OTA."
>
> ---Hmmmm, interesting. Do you have a schematic of this in action?

http://home.debitel.net/user/jhaible/jh4_vcf_vca_schemo4.gif

This is not a pitch modulation application (what Martin was talking about),
but it's still an example where I thought it would be practical to swap the
inputs of a 13700. The dual OTA is used to select one of two envelopes
for the VCA and set the modulation depth of the envelopes with one
manual knob (or one CV), center zero, with a little deadband. I wanted
to avoid the envelope shape being compressed by the OTAs' input
nonlinearity,
so I used the Iabc inputs for signal (i.e. envelopes) and the signaöl inputs
for manual control.

JH.