The Radial JDI Stereo (part R800 1012 00) is a two-channel passive direct box built around two Jensen audio transformers, for live concert touring and professional recording. It converts unbalanced instrument signals - acoustic guitar, bass, stereo keyboards, laptops - into balanced, low-impedance XLR signals for long cable runs to the mixing desk, with 1/4-inch thru outputs for on-stage amplifiers. Because it is passive, it needs no power, and the transformers block stray DC and break ground loops, which makes it particularly effective at eliminating hum and buzz. Each Jensen transformer has a nickel core, dual Faraday shields and a MuMetal can, giving very low distortion and the ability to handle extreme transients. Radial specifies 20 Hz to 20 kHz response within 0.2 dB, 135 dB dynamic range, a maximum input of +21 dB, 140 kilo-ohm input impedance and 150 ohm balanced output. Controls are an input pad and ground lift per channel. The 14-gauge steel chassis with internal I-beam construction measures 127 x 84 x 46 mm. Radial provides a three-year transferable warranty.