USB powered, software controlled, but it does have a switch for phantom plus gain knobs, so maybe it will work independently of a computer.
2 Mic Inputs with +48v Phantom Power
2 Guitar/Bass Inputs – use the high gain input for guitars and basses with high level pickup outputs, or the normal input
Stereo Line Inputs for your line out level gear
Stereo Digital Output S/PDIF via RCA
Stereo Line Outputs via balanced 1/4-inch
Stereo Monitor Input via stereo 1/4-inch jack
Headphone Output with independent
volume knob
VU Meters assignable to input, record send, output and monitor levels
Footswitch Jacks send MIDI commands to recording programs (start/stop, punch in/out, etc.)
Pro Audio Performance with over 100dB signal-to-noise & dynamic range
Unique, full tone low latency monitoring regardless of recording software's buffer size
44.1 & 48KHz, 16 & 24 bit recording
96KHz mode with built-in sample rate conversion for simultaneous input and output
USB-powered
Rock-solid Drivers: ASIO, WDM, Mac OS X
UX2 PREMIUM FEATURES
TonePortâ„¢ UX2 has all the features of its little brother UX1, plus a whole lot more!
STEREO MIC IN
The 2 mic ins are perfect for vocals and other mic'd sources, with +48v Phantom Power to drive the finest microphones. Use them for mono or stereo sources, and tone process them together or separately.
DIGITAL OUT
Connect UX2's digital out to your hardware digital recorder for direct digital recording of your premium Line 6 tone, as well as playback from your computer. Provides S/PDIF digital audio at 44.1/48KHz sample rates perfect for CD, DAT and many popular digital recording setups.
EXTRAS
Some are obvious, like the hardware VU meters and footswitch jacks. You'll appreciate others when you need them, like guitar/bass inputs that handle high output instruments, separate volume control for the headphone out, and assignable metering.
http://www.line6.com/toneport/hardware.html