Yamaha CS80

Hi all:
As stated before I'm in the way of use a PAiA MIDI2CV8 to control via
CV the 4 voices of my CS-50, because the KAS is dead.
Actually I'm controlling 1 voice with the CV out of a Novation 
BassStation, and using a potentiometer to tuning the voice.
There is a simple way of tuning all the voices without set a 
potentiometer for every one? Preferably 1 potentiometer for all voices.
I can't use the pitch control of the CS-50 because is connected to the
KAS.
In other matters, I read that in the manual of the CS-80 are graphics
that descibes how the presets are made. Can I use this to reconstruct
the presets of the CS-50?. I don't have the CS-50 manual, and I want
to use some of the presets as a starting point to do new sounds.
Thank you.

Sebo