Model 15 - Mellow Keys - modify pitch drift

Hello Forum:

  1. I Never really tried programming/tweaking a patch before on any synth
  2. Love the Mellow Keys patch in Model 15
  3. Need to reduce the amount of pitch drift/chorus effect for a song I’m working on
  4. after an hour or so I haven’t been able to determine which knob(s) controls that.
    5 Who can provide some guidance?