Anyway to achieve a vintage mode effect?

[grayxr]

I recently acquired a Prophet 12, and I wish I could use a vintage mode control to introduce some of the per-voice variations that can be immediately present on Tom Sawyer-like unison patches. Has anyone used the modulation matrix or some other trick to simulate the vintage mode on newer Sequential synths?

[LoboLives]

On my Prophet X I set Slop as a source to modulate the Filter and amp envelops amount, attack, decay and release individually and simply dial in each to taste. Seems to work well enough.