The controller communicates via USB, has 9 endless rotary encoders, 9 push buttons and a joystick. It is USB bus powered for convenience. A single press of one of the 9 encoder knobs will select any MIDI channel from 1 to 9, (or pressing two knobs selects channels 10-16) LEDs indicate which MIDI channel is currently active. The encoders also remember where they were when they were last used on that channel and display their position on the ring of leds around each knob, so you can change channel without fear of data jumps. The self-centering joystick sends information on the currently selected MIDI channel. It can be set as either two controllers (19 & 20) with centre position value 64; as 4 controllers (19 to 22) with centre value as zero; or as 4 switches, sending value 127 at its extremes on controllers 19 to 22, depending on direction. The 9 push buttons send data on the selected MIDI channel and can remember their on-off status, which is shown by internal LEDs. Each button can be set as one one of three modes on only, on and off, or toggle. You can enable controller update mode so that information changed on your computer will update the values stored in the Killamix Mini. With the 9 channels available at the push of a single knob, you effectively have 81 endless controllers and 81 buttons at your fingertips in a very compact unit. (or 144 at the push of two knobs together). The whole unit is attractively styled in a sturdy aluminium box, finished in brushed aluminium and with matching solid aluminium knobs. Killamix Mini on Darren Prices (Underworld) console at 0:54 (and elsewhere)