Does the voice randomization modulator only work on certain parameters? When I attach it to pitch, it randomizes the pitch as I would expect it to. But when I attach it to say, the delay effect time, there is no randomization.
The FX processors are monophonic.
Voice Randomization (VR) creates a pseudo-random SEQUENCE whose number of steps is determined by the number of POLYPHONIC voices set on the Voice Page, and it only works in the Polyphonic Area. Each time a key is pressed the sequence advances to the next step. e. g. if the number of voices is set to 3, then the sequence will consists of 3 steps with 3 "fixed" values, and it will cycle through these steps.
If you want to create a NEW random value every time a key is pressed (not a pseudo-random sequence), use a Random LFO with it's Play Mode set to 1shot, and Amp Jitter set to 100%. This works on both the Polyphonic Area and Monophonic Area.
Random LFO with it's Play Mode set to 1shot, and Amp Jitter set to 100%, is basically the equivalent of TrR (Trigger Random) modulation source in Massive.
I might be completely wrong on this but to me, VR seems to produce a static number. Like if I set a range modulation, it will choose one spot per key press.
"I might be completely wrong on this but to me, VR seems to produce a static number. Like if I set a range modulation, it will choose one spot per key press."
That's how it works. And, the amount of static numbers depends on the amount of voices you set in Massive X.
As has been mentioned, if you're looking for full randomization, VR is the wrong thing to use.