A brown box was a simple electronic circuit built by telephone enthusiasts to connect two separate phone lines. When someone called either line, both phones would ring, and answering either would bridge the audio. Phreaks used them to create unauthorized conference calls or hide their location by routing calls through an intermediate drop.
Heard on the job
He wired up a brown box in the basement so we could conference in the whole group without the operator knowing.
Related terms
Blue box
A historic electronic toll-fraud device used to manipulate long-distance telephone switches.
Beige box
A modified telephone equipped with alligator clips for tapping directly into telephone lines.
Gold box
A historic phreaking device that acts as a line diverter to route incoming calls to a different number.