Radial Engineering SB-5 Laptop DI Stereo Direct Box

The Radial Engineering StageBug SB-5 Laptop DI is a stereo passive direct box built specifically for connecting consumer-level audio sources—laptops, tablets, smartphones—to professional PA systems and mixing consoles. It features an integrated 1.5-meter 3.5mm stereo cable that plugs directly into a device's headphone output, converting the unbalanced stereo signal into balanced audio through custom wound transformers. Outputs include stereo 1/4" TRS jacks for local monitoring and an XLR output that delivers a mono sum of both channels for feeding a single mixer input.

Signal quality is maintained through Radial's transformer isolation, which breaks the electrical connection between source and destination to eliminate noise and interference. A -15dB pad tames hot output levels to prevent clipping at the mixer input, while dual ground lift switches independently address ground loop hum on each channel. The entirely passive circuit means there are no batteries to replace or phantom power requirements to manage. Compact enough to toss into a laptop bag, the SB-5 is designed for presenters, DJs using laptop playback, and any situation where consumer audio needs to reach a professional sound system cleanly.