Can I use the unit without connecting it to a power outlet?

Yes. Simply connect the USB port (for PC/Mac) to your computer with the supplied USB cable.

Power can be supplied from an electrical outlet to the other USB port (the one for power supply) using a USB power adapter (sold separately).
This enables easy DJ changeovers because computers can be switched without turning off the unit.
You can also use the unit as a standalone mixer without connecting a PC/Mac.