The Singing Machine SML650 Instruction Manual page 8

Connection
Connecting to AUX IN Jack
AUX IN
Cradle
Connect an external device by using an
appropriate cable (3.5mm audio cable not
included) as shown.
Note:
See page E14 to select and use the Aux In
AUDIO OUTPUT
/ HEADPHONE JACK
function.
To External Unit
OR
— E7 —