Yamaha PORTATONE PSR-248 Mode D'emploi page 16

Selecting and Playing Voices — The Voice Mode
There are three ways to select voices: 1) directly
entering the voice number with the numeric
keypad, 2) using the +/- keys to step up and
down through the voices, or 3) pressing the
VOICE button to advance through the voice
numbers.
Using the numeric keypad
Enter the digits of the voice number as printed
on the panel. For example, to select voice #42,
press "4" on the numeric keypad, then "2."
042
NOTE:
When selecting Voice numbers 1 - 10, the PortaTone pauses
briefly before changing to the voice. (However, you can
quickly select the voice by pressing all three digits; for
example, select voice #9 by pressing "0," "0," then "9.")
Pressing only "0" does not change the voice.
16
Trombone
TEMPO
116
Using the +/- keys
Press the + key to select the next voice number,
and press the - key to select the previous voice.
Holding down either key continuously scrolls up
or down through the numbers. The +/- keys
have a "wrap around" feature. For example,
pressing the + key from the voice 100 returns to
voice 1.
Using the VOICE button
Press the VOICE button to select the next voice
number. (This functions exactly the same as the
+ button.)
NOTE:
Each voice is automatically called up with the most suitable
octave range setting. Thus, playing middle C with one voice
may sound higher or lower than another voice at the same
key.