Casio PX-780M User Manual page 66

Reference
Problem
Even though I play on different
ranges of the keyboard, the
notes do not change octaves.
E-64
Cause
The ranges of certain tones are limited, which means that octaves change normally up to a certain
low note or high note. With such a tone, the notes of the lowest octave will be repeated to the left of
the lowest possible note, and the highest octave will be repeated to the right of the highest
possible note. This is due do limitations in the range of the original musical instrument for each
tone, and does not indicate malfunction of the Digital Piano.
Action
See
Page