The USB IV takes instrument or mic level signals and converts them with a 32 bit ADC containing sample rates from 44.1kHz to 192kHz for computer input. USB audio is converted using a 32-bit stereo DAC to analog audio. Custom transformers remove ground loops and other system noise between the digital and analog noise between the digital and analog audio systems The USB IV is a high-quality 4 input / 4 output 192kHz capable digital interface. The inputs can accommodate any combination of uses including 4 microphone inputs or two high Z instruments and two line inputs Low latency monitoring is implemented by mixing the inputs with the outputs and is controlled by front panel switches. Channels 1 & 2 are balanced transformer isolated outputs. Channels 3 & 4 are sent out through the headphone output jack. The USB IV provides both MIDI IN and MIDI OUT through rear panel connections. The sample rate is set via the USB interface and its low latency ASIO/WDM driver. Product Specifications: Computer Connectivity: USB 2.0 Simultaneous I/O: 4 x 4 Number of Preamps: 4 x mic/instrument Phantom Power: Yes A/D Resolution: 32-bit/192kHz Analog Inputs: 4 x XLR-1/4" combo (mic/line) Analog Outputs: 2 x 1/4" Headphones: 1 x 1/4" MIDI I/O: In/Out USB: 1 x Type B Bus Powered: Yes Power Supply: USB bus-powered