Sony HAP-S1 User Manual page 24

You can connect other playback equipment such as the Super Audio CD player to the HDD
AUDIO PLAYER and enjoy playback from that equipment through the speakers or headphones
of the HDD AUDIO PLAYER.
Note
Make sure that the AC power cord (mains lead) of the HDD AUDIO PLAYER is unplugged
when connecting any other cord.
Only the LPCM 2ch audio format can be played when the signal is input through the
OPTICAL IN or COAXIAL IN jack.
Playing other formats may produce noise or even damage the speakers if played at a high
volume.
Connect another audio player to the OPTICAL IN jack, COAXIAL IN jack or LINE IN jacks on
the rear panel of the HDD AUDIO PLAYER.
When connecting through the OPTICAL IN jack
: OPTICAL IN jack of the HDD AUDIO PLAYER
: Optical digital cable (not supplied)
: Optical digital output jack of other equipment
When connecting through the COAXIAL IN jack
: COAXIAL IN jack of the HDD AUDIO PLAYER
: Coaxial digital cable (not supplied)
: Coaxial digital output jack of other equipment