Radial Trim-Two: Clean Sound From Any Playback Device

The Radial Trim-Two is a passive stereo direct box that connects laptops, keyboards, DJ mixers, tablets, and other consumer playback devices to a professional balanced sound system, complete with a front-panel level control for instant adjustments on stage. Built around two isolation transformers, it strips the hum and buzz that ground loops inject when you patch a computer into a PA, and it does so without any power supply to fail or forget. The moment your laptop feed goes from buzzing to dead-silent, you understand why the Trim-Two earns a permanent spot in the gig bag.

How Transformer Isolation Kills Ground Loops

When a laptop or keyboard shares a power circuit with the sound system, a small voltage difference between the two grounds pushes current through the audio cable, and that current becomes the familiar 60-cycle hum. The Trim-Two places a transformer in each channel so the audio couples magnetically across the isolation barrier while the ground path is broken. With no direct electrical connection between source and PA, the loop is eliminated rather than masked, and a switchable ground lift lets you break the shield connection as well for stubborn cases. The result is a clean, balanced signal that stays quiet over long cable runs.

Level Control and Mono Sum

Consumer devices rarely output a predictable level, so the Trim-Two puts a stereo level control right on the front panel, letting you match a hot DJ mixer or a quiet tablet to the console without asking the engineer to re-gain the channel. An input pad adds headroom for especially strong sources, keeping the transformers clear of saturation. The mono sum switch collapses the stereo pair into a single mono feed for a mono PA, or splits one balanced output to two destinations when you need the same signal in two places, a small switch that solves a surprising number of real-world routing problems.

Connect Almost Anything

The input side offers three connector types, dual 1/4-inch jacks, left/right RCA, and a 3.5mm stereo mini, so nearly any consumer source patches in without an adapter hunt. Whether the signal arrives from a headphone jack, a pair of RCA outs, or a set of line outputs, the Trim-Two accepts it and delivers two balanced XLR outputs to the mixing console. That flexibility makes it a universal bridge between the messy world of consumer connectors and the tidy XLR inputs of a professional stage.

Road-Ready Passive Build

Because the Trim-Two is entirely passive, there is no wall adapter, no phantom-power requirement, and no battery to die mid-show, so it simply works the instant it is patched in. The chassis is folded from 14-gauge steel with Radial's book-end design, which raises protective walls around the connectors and controls so foot traffic and cable tension never reach the jacks. It is the kind of set-and-forget tool that survives years of load-ins without complaint.

Who the Trim-Two Is For

The Trim-Two is built for the keyboard player running backing tracks off a laptop, the DJ feeding a house PA from a controller, the AV presenter sending a tablet into a conference system, and the worship or corporate tech who needs consumer playback to sound as clean as the rest of the rig. Anyone who has fought hum from a computer feed will recognize the value of a passive box that fixes it and adds a volume knob in the bargain. Plug-and-play from the first show, it turns unpredictable consumer audio into a reliable, balanced source.