Click the disclosure triangle at the lower left of Vintage Electric Piano to show or hide the extended parameters.

Extended parameters
Delay PP slider and field: Drag to set the delay time (in milliseconds) when the keys are struck pianissimo (PP-soft).
Delay FF slider and field: Drag to set the delay time (in milliseconds) when the keys are struck forte (FF-hard).
Midi Mode pop-up menu: Determine how Vintage Electric Piano responds to MIDI controllers. Choose from: Off, Modwheel to Tremolo, and Full Remote.