The IB-04 is a multifunctional device. It is simultaneously a DI-Box, a head-phone amplifier, a mixer, a preamp and a boostertype appliance. It can handle two instrument input signals at the same time. The symmetrical output signal from the XLRsocket can be switched to three different operating levels: 0dB, -20dB and -40dB. The signal from the line output (mono or stereo) can be boosted up to 20dB. Additionally there are two tone-controls for this output.