Breakout box

A breakout box (BoB) is usually a box, in which a compound electrical connector is separated or "broken out" into its component connectors. Compound connectors (which are often proprietary) are used where sufficient space for (or access to) connections is unavailable, such as on personal computer sound cards. If there are only a few connections, then a breakout cable (also octopus cable) may be used, as is common on smaller notebook computers.

In the sound card example, a DA15 connector on the outside of the board is often broken out into DIN connectors for MIDI. Some professional audio applications use rackmount breakout boxes. A patch panel can also function as a breakout box, in the case of multi-channel DB25 (or other) connectors used for multi-track recording.

A docking station for notebook computers that draws the signal for multiple connectors from the pins of one connector is a type of breakout box.

A breakout box can mean a piece of electronic test equipment used for diagnosing problems in computer communications, typically over a serial port. The breakout box sits between two pieces of equipment and usually has some LEDs to display the status of the different signals in the serial cable. It will also often have DIP switches to let the user connect or disconnect different signals in the cable, and it will usually have connector pins that let the user short pins together using electrical jumpers, or gain access to individual signal lines with an oscilloscope or other test equipment.