Phantom Power and Plug-in Power refer to different methods and voltage that the recorder uses to power different types of microphones.
When the recorder uses phantom power, it sends either 48V or 24V to the left and right XLR input jacks on the bottom of the recorder. The amount of voltage is set using the Mic Power menu option. To enable phantom power, use the 48V/24V switches on the left side of the recorder.
When the recorder uses plug-in power, it sends lower current to the MIC input jack on the left side of the recorder in order to power microphones that have 3.5 mm diameter plugs.
Verification Source: Olympus America Website
Test Date: 5.10.12