hello, i use a analogue systems controller called the french connection when i play out and i would like to use the moog slim phatty with it. i know it has cv in but i dont want to buy it if it doesn’t work with it. please help!
The only thing that worries me about the French Connection is that it puts out a maximum of 10V, where the SP and LP require only 5V. I would put an attenuator in the connections going to the Phatty, to lower the max output to 5V. 
@yesak67, the most important question is how exactly would you like to be using the French Connection with the SP? As Voltor07 suggested an attenuator will help with the voltage variations. I’m also not sure if the SP (or the LP for that matter) has a 1Volt/octave CV input so the FC’s keyboard may not track the oscillators with consistency.
Otherwise, You could buy a Voyager and VX-351 for less than the cost of a French Connection and have the KB, albeit without that cool ring manipulator.
The LP has a 1V/oct CV input, up to 5V. I’m assuming the SP has the same architecture.
The LP is .97v/oct. It will track 3 octaves after that, many can hear the deviation. For the music I make it does not matter.