Here’s a block diagram of the VPM (Variable Phase Modulation) oscillator, one way the Prologue Multi Engine can be run. This of course is run in software – meaning it’s digital.
There is an awful lot here (i am trying to get my mind around it), but it looks to me that this is capable of a wide variety of sound generation. Like for instance notice the drive at the end. The little circles with the X’s in them are valves, where you can adjust levels and amounts. The manual says in addition, “Sixteen oscillator types are available for this VPM oscillator.” Not sure what this really means but that sounds nice. Not sure how difficult this will be to program, if it’s some sort of gnarly thing where you change one parameter a little, and something strange and unexpected happens, or if it’s one of those things where you have an idea, and you can go in and dial just what you thought of.
So beyond the multiple separate User programs there will be a variety of settings for the VPM on the Multi Engine. Should be a very interesting beast.