DJDI: 2-Channel Direct Box

DJs, keyboardists, computer musicians take note: The direct box you’ve been waiting for is here! Sporting two channels, the DJDI easily and inexpensively solves the problem of converting unbalanced signals into balanced output suitable for use with mixers, PAs, recording consoles, and more. Continuously variable rotary input signal attenuator allows the DJDI to accommodate virtually any source signal level; passive design means clean, quiet, uncolored operation with no power required.

More info here