Yamaha RY8 Owner's Manual page 25

POWER-ON PROCEDURE.
There is actually a correct process for switching the various components in an
electronic music system on and off. The rules are simple but important.
BEFORE TURNING ANYTHING ON:
Be sure that all components are actually plugged in, and check to make sure
that all volume controls are turned down to their zero positions.
Always turn the RY8 on first (followed by any additional devices which may
be connected).
Always turn the sound system on last.
Raise the sound system volume to a reasonable level.
Gradually raise the RY8 volume while playing the drum pads to set the
desired listening level.
When turning the various components off, simply reverse the process. The
reason for turning the RY8 on first and off last is to avoid the possibility of
sending a power surge through the sound system which could damage the
amplifier or speakers.
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