Yamaha 503 Reference Manual page 14

Disabling Automatic Selection of Voice Sets (Effects, etc.)
Each Voice is linked to its default VOICE SET parameter settings. Usually these settings are automatically
called up when a Voice is selected. However, you can also disable this feature by the operation in the relevant
display as explained below.
For example, if you want to change the Voice yet keep the same Harmony effect, set the HARMONY/ECHO
parameter to OFF (in the display explained below).
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Call up the operation display.
[FUNCTION] → [E] REGIST SEQUENCE/FREEZE/VOICE SET → TAB [E][F] VOICE SET
2
Use the [A]/[B] buttons to select a keyboard part.
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Use the [4 ▲▼]–[8 ▲▼] buttons to enable/disable automatic calling up of the settings
(ON or OFF) independently for each parameter group.
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CVP-509/505/503/501 Reference Manual
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