The Whirlwind pcDI is perfect for interfacing the outputs of CD players, computer sound cards, iPODs® / MP3 players, tape decks, etc. with professional, balanced, low impedance equipment. This unit contains two separate DIs - input your signals with one 3.5mm (1/8") mini TRS stereo jack, two sets of color coded RCA phono type input and through jacks or 1/4" TS input jacks. Output is via corresponding color coded XLRs.Impedance Ratio (input to output, per channel): 133:1Frequency Response: 20Hz-20kHz ±1dBLevel Change (input to output): -20dB (pad out), -40dB (pad in) Ground Lift switch to help eliminate hum and buzz Color coded RCA phono in / through jacks 3.5 mm input jack 20dB pad switch for connection to "hot" input signals Color coded XLR output jacks Stereo/Mono switch for stereo operation or safely combine both inputs into a mono signal sent to both outputs Uses Whirlwind's TRHL-M transformers with metal shield