Commodore AMIGA Introduction Manual page 20

On most stereo systems, there are extra inputs, often labeled" Auxiliary" or
"Aux," to which you attach one end of each cable . . On the back of the
Amiga are
two audio connectors,
one for the left audio signal and one for
the right audio signal. Insert the other end of each cable into the
appropriate audio connector:
Sound Connections for Monitors
Some monitors, including the Amiga Monitor, have a built-in speaker. To
connect a monitor for sound, you need:
• a "Y" adapter that converts the two stereo channels from the
Amiga to a single channel
• a cable for connecting the "Y" adapter to the audio connector
on the monitor
You can get "Y" adapters and connecting cables from many stores that
carry radio and electronic parts.
Setting Up the Amiga 2-11