So as of last year I am the proud owner of a MNM and enjoy using it very much.
Today I got the idea of creating a shepard tone with it but can’t quite think of the best way to do it. Right now I’m fiddling around with the LFOs on the SIN-Machine with Volume and Pitch Automations but can’t get it right.
I’m sure it can be done and someone here is fill me in on how to achieve it 
They really should be called Tenney Tones. James Tenney’s piece “For Ann (Rising)” is the first example of the illusion.
You need two lfo’ per voice. Saw for pitch and sin/triangle for the amplitude. You need to closely control the phase relations between the voices so that the first voice is all the way faded out by the time the third voice is starting to fade in. On the MnM I would use 4 voices with identical lfo settings that are triggered on steps 1,17,33, and 49. Lfo lengths should cycle over 64 steps. Good luck!
Thanks a ton. Will give it a try tomorrow and report back
I’m tempted to try this on a Digitone…