1) Connect the guitar (bass) output with short (less than 12 ft), instrument cable to the input of the direct box (DI).
2) Connect the balanced (XLR) cable from the output of the DI to the appropriate input on the snake or stage box.
3) If a 60hz hum is present, most direct boxes have a ground lift switch that should be engaged.
4) If the DI is active and is powered from the console via phantom power, ensure that the console input channel has phantom engaged. Alternatively a remote phantom supply may be used to supply power directly to the DI onstage.