ART TubeOpto 8, Eight Channel input / output expander for any ADAT lit-pipe equipped audio interface, Eight Fully Featured Class-A Tube Mic Preamps, Eight Channels of ADAT lite-pipe Digital 24 Bit Audio I/O at 44.1 or 48kHz, Input Gain and Output Level Controls on Every Channel, Input Pad, Phase flip and Low Frequency Roll Off Switches on Every Channel, Two Additional Front Mounted High Impedance Instrument Line Inputs, Eight 1/4-inch TRS Balanced Outputs