The StageBug SB-5 Laptop DI from Radial Engineering is a compact stereo direct box designed to accommodate laptop computers, tablets, and other consumer audio products when amplifying the signal through a PA system.

The passive design begins with an integrated input cable that connects from the headphone out via a flexible 5’ (1.5m) cable that is terminated with a standard 1/8" (3.5mm) stereo connector. The cable is secured via a clamping strain relief and is wrapped using the sidewinder cleat for easy storage. This eliminates the need to locate a cable, thereby making it easy to deploy in fast-paced work environments. Inside, the signal is sent to a pair of custom-wound transformers where the impedance is lowered and the signal is balanced for long cable runs, upwards to 300’ (100m). The transformers further benefit by isolating the computer from the PA system to help eliminate hum and buzz caused by ground loops. This is augmented with a ground lift switch to further reduce ground contamination.

A choice of output connectors is available including a stereo set of 1/4" TRS jacks for full stereo operation or an XLR out that automatically sums the left-right program material to mono. This can save valuable channels on the PA system and makes setup easy in situations where full stereo reproduction is not required. A -15 dB input pad can be engaged to reduce sensitivity and enable extra high output sources to be connected without distortion.

These features combine to make the unit suitable for the AV technician, media manager, or traveling musician equipped with a computer.