The OTG is needed, the connector found in the majority of USB external drives is the USB Type A plug while the DX50 has a micro USB type B jack. The OTG provides you with a USB Type A jack to a micro USB Type B plug.
The USB 3.0 external drive comes with a cable that is compatible in a USB 2.0 type A jack.
I like the Seagate Backup Plus portable drive, you can switch the drive onto the Sata receptacle and you are good to go.
Edited by musicheaven - 8/25/13 at 11:19am