Yamaha VCA help

[omissis]

Hi all
I'm not skilled with electronic but I'd need to know what is happening inside the infamous iG00151 VCA made for the CS synthesizers series. The VCA IC looks like on the attached block diagram picture; so if a voltage is put into the VCA, it does convert it in current, so the output is a current.
How the converting calculation is done inside the OTA?

Again, if you look at the second picture you will see that voltages (detune and initial pitchbend) mix with currents (Aftertouch and SubOsc Function) at the node "N".

Questions are: how do I calculate the correct voltage at the node "N" to be delivered to the VCO?

Last one: what's the role of the 0.001K capacitor after the VCA?

Thanks for any reply

Max

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