The Rapco LTI-100 Laptop Interface is a portable, battery-powered direct box and interface specifically designed to solve the common problems of connecting a laptop or portable media player to a professional sound system. It addresses three key issues: converting an unbalanced stereo output to a balanced mono or stereo signal suitable for a mixer's mic/line inputs, providing ground lift isolation to eliminate hum caused by ground loops, and offering a convenient, phantom-powered pass-through for a microphone. The device features a stereo 1/8" (3.5mm) input for the laptop and two balanced XLR outputs (Left and Right), allowing the audio to be sent to two separate channels on a mixing console for proper stereo imaging or summed to mono.

A standout feature is its built-in, switchable ground lift for each channel, which is often the fastest remedy for the intrusive hum that can occur when connecting a laptop to a PA system. The LTI-100 also includes a female XLR input with +48V phantom power pass-through, enabling a condenser microphone to be connected directly to the unit and then sent to the mixer alongside the laptop audio, simplifying the setup for presenters or performers who need both playback and a live mic. Powered by a standard 9-volt battery, it operates completely independently of AC power, making it ideal for mobile DJs, presenters, and musicians who need a reliable, hum-free connection in any venue.

For anyone who regularly presents or performs with a laptop, the Rapco LTI-100 is an essential troubleshooting and interface tool. It cleans up the signal, prevents hum, and provides a streamlined, professional connection point. By consolidating several critical interface functions into a single, rugged, and portable device, it ensures that laptop audio is integrated into a sound system with clarity, reliability, and minimal fuss.