Also called a direct box.
(1) The use of some form of mechanical or electrical pick-up mechanism on an instrument for the purpose recording or amplification. DI also refers to the connection of an electronic keyboard or power amplifier feeds to a mixer. A DI consists of (usually) a small electronic box into which an instrument is plugged and the electroacoustic pick-up attached to the instrument itself. Pick-ups can be electro-magnetic, as on electric guitars, piezo devices, and also contact microphone, also called bugs. All types of pick-up have unbalanced outputs at mic-level (~-50dBu), so the DI box has to balance the signal and drive it to the mixing desk. DIs can be passive or active in the typical sense. Active DIs have some form of electronic amplification built-in; this is only a buffering amplifier, separating the instrument pick-up from the rest of the DI, yielding no significant gain. Active DIs offer better sound and playability over passive devices, but require batteries, phantom power, or some other means of powering the internal amplifier.
(2) Any device used to convert unbalanced lines to balanced lines.« Back to Glossary Index