LC Prime&reg; Dolby Stereo Surround Audio Processor USB Decoding DAC Independent Amp A992 aluminum silver 1 Dolby 2.0 surround sound technology with 3D stereo enhancement processing and 3D virtual surround sound processing Decode Dolby Pro Logic and Dolby digital AC-3 mixed signal and 3D virtual surround sound processing Produce stereo surrounding effect with only two speakers instead of 5.1 speaker system. Refined signal that reserve and enhance sound effect Wide range of use: adaptable to regular RCA input and USB input from Window and Mac OS Small and portable can put on desktop, study, home, office or anywhere you want