Yamaha PortaSound PSS-51 Owner's Manual page 9

GETTING STARTED
Ш CONNECTING HEADPHONES AND AUXILIARY EQUIPMENT
Headphones:
Standard stereo headphones can be connected to the rear-panel HEADPHONES/AUX. OUT jack.
The internal speaker system will automatically shut off when the connection is made. This is
especially convenient for private practice or playing late at night.
Auxiliary Equipment:
The HEADPHONES/AUX. OUT jack can also be connected to a keyboard amplifier, stereo sound
system, mixing console, or tape recorder.
Caution:
To prevent any possible damage to speakers, be sure that the volume controls for the PSS-51 and ALL
auxiliary equipment are turned down before making connections.