The Radial JDI Stereo is a passive stereo direct box designed to handle extreme signal levels without distortion of any kind. Unlike an active DI that is limited by the buffering amplifier's rail voltage, the JDI employs a pair of Jensen audio transformers that at once balance the signal and lower the impedance to drive long cables. No power is required. You simply plug in and it works. Jensen Transformer equipped passive DIEliminates hum and buzz from ground loopsVirtually zero phase harmonic distortionCompact stereo format for twice the performanceThe magic comes from the amazing Jensen transformers inside. Jensens are legendary in their ability to gracefully handle transients while delivering a smooth, warm sounding Bessel curve, reminiscent of the finest vintage gear. Ruler flat from 10Hz to 40kHz and with virtually zero phase deviation, the JDI Stereo delivers the natural, pure sound of the instrument without artifact. In addition to converting the unbalanced Hi-Z signal to low, the transformers also serve to isolate the input from the output, essentially filtering out stray DC voltage that can cause noise and lead to so called ground loops. This allows audio to pass while eliminating problems. Features include input and thru-put connectors plus a -15dB input pad on each channel. This is supplemented with a ground lift switch that lifts pin-1 on the two XLR outputs to further reduce hum and buzz caused by ground loops. Built tough to handle the abuse of live touring, the JDI Stereo employs a 14-gauge steel I-beam inner frame and a unique book-end outer shell. The innovative design eliminates stress on the PCB, reducing opportunity for solder joints to go 'cold' while the outer shell creates a protective zone around the switches and connectors.