the manual says:
USB CONNECTOR
Connect your mixer to a computer using a standard USB cable. This enables a stereo signal to be sent to and from your mixer and computer. The signal sent from the mixer to the computer is the same as the main bus. The audio returning from the computer into the mixer appears directly in the main and/or control room bus (depending on USB/2TR to MAIN and PHONES/CTRL RM buttons).
NOTE: The mixer cannot be bus-powered via USB! Always use the included power adaptor to supply power to the mixer.
i had a behringer mixer with built in effects for some time, and it was a noise hell. because of that fancy built in fx. now i'm a bit more carefull with all-included devices. some reviews of those xenyx mixers stated noise issues over usb. but people hear things differently.... that power socket looks quite unique on those units. behringerspezial.
somehow a bit chewed up but still true: buy equipement from a trustworthy shop in your town: you can talk stuff, and even try them out.
edit: i think, those bespoken xenyx units are a so called no brainer for a start into mixing/recording? sometimes routing signals back and forth can be a bit confusing (or a earpiercing experience) but that's a part of it.
