Kawai DP1 Owner's Manual page 37

9. LINE OUT jacks
These outputs are used to connect the DP1 to a 5.1 channel surround sound system.
10. LINE IN jacks
These inputs are used to connect external audio devices (CD-player etc.) to the DP1.
11. HEADPHONES jacks
There are two jacks for headphones provided at the left end on the bottom of the piano.