Sweetwater Sales Engineer Nitish Kulkarni explains what the D.I. input on your audio interface is, and when to use it.
Often abbreviated DI (for direct insertion), a DI is a device commonly used to convert high impedance unbalanced signals from a stage instrument (like a bass or keyboard) into a low impedance balanced signal. A DI box puts the signal at the proper voltage level for the mixer and prevents the instrument from becoming loaded down with too low impedance, which could cause tonal shifts and distortion. Direct insertion also allows the signal to be transmitted over long lengths of cable. DI boxes are used in live sound to get a signal out of an instrument on stage out to the mixing board, which can be as much as 500 feet away. A simple direct box consists only of a small transformer, but more sophisticated designs of direct boxes employ electronic gain stages that more closely resemble the input section of a modern instrument amp. A DI box may also have some combination of ground lift switches, equalization switches, level matching switches, isolated line outputs, and more.