The IMP-JT from Whirlwind is a single channel, passive direct box featuring a Jensen transformer. The transformer is well known for providing a wide frequency response and superior noise reduction.
The unit provides two 1/4" jacks, one for input and the other for a "loop through" of the signal source. The jacks are wired in parallel and either can be used for either function. The male XLR jack delivers a low-impedance, balanced output for connection to a mixing console or workstation.
A ground lift switch cuts the ground connection between the input and output of the unit when set to the LIFT position, eliminating any ground loop that could be present in the circuit.