Use the following procedure. (*This is not possible for the S30, since it has no mic input.)
(1) Install the VH board into slot 1 of the synth (fixed at slot 1).
(2) In Performance mode, select any performance.
(3) Press JOB, select INITIALIZE, choose "CURRENT PERFORM," and press ENTER>YES. (* This initializes the selected performance. Part 10 = drums, and other parts will use a piano sound.)
(4) Press EDIT, turn knob A to access the "PART AD," use the PAGE knob to move to the "MIX Template" page, and use knob B to change audio->mic and knob C to change off->mic.
(5) Turn knob A to select "PART 01," use the PAGE knob to select the "MIX Level 1" page, and use knob B to set VOL=0.(Alternatively, select the "LYR Mode" page, and turn PART 01 to LAYER=OFF (knob 1) and RCH=OFF (knob 2).)
(6) Use knob A to access "COMMON," use the PAGE knob to select the "EFFÅ@Part" page, and set PLG-EF=part AD.
(7) Use the PAGE knob to access the EFF PLG page, and use knob 1 to change THRU->VOCODER.
(8) Press ENTER, use the PAGE knob to change pages so that LEAD/HARM appears above knob 2, and turn knob 2 to select L