On the external audio source device, connect the analogue cable or optical cable to either the LINE out, AUX out, Headphone out or REC out jack.
On the HDD, connect the other end of the analogue or optical cable to the LINE IN/OPTICAL jack.
Your HDD will detect the connection and enter the RECORD MODE Menu automatically.
Select Record from LINE IN or Record from Optical and then press the right arrow key to enter the record mode.
Press the down arrow key.
Start the playback of the external audio source to record.