Yamaha PSR-S650 Reference Manual - Page 11

Harmony/Effect-Related Settings Selecting a Chorus type The Chorus effect creates a thick, textured sound that is similar to many of the same Voices being played in unison. When you select a Style or Song the optimum Chorus Type for the Voice used is automatically selected. If you want to select a different Chorus Type, use the procedure described below. 1 Press the [FUNCTION] button to call up the Function display. 2 Press the CATEGORY [] buttons repeatedly to call up "Chorus Type." The currently selected Chorus type will be displayed. Chorus type Selected Chorus type 3 Use the dial to select a Chorus type. Refer to the Effect Type List in the separate Data List for information about the available Chorus types. Try playing the keyboard with the Chorus function.  Adjusting the Chorus Level You can individually adjust the amount of Chorus that is applied to the Main, Dual, and Left Voices (See page 3). 4 Memorize the settings here to the Registration Memory as desired. If you select a different Style without saving, the settings in steps 3 will be cleared. Reference Manual 11