Going Direct In With The Radial Engineering HDI Direct Box

Vintage KIng - Going Direct In With The Radial Engineering HDI Direct Box

August 25th, 2021

This video and write-up originally appeared on

By Tyler Lind
Published August 2021

If you’re looking to solve a problem in the studio or on stage, it’s highly likely that Radial Engineering already has an answer for you. Since 1996, the British Columbia-based company has been crafting practical and road-ready direct boxes, splitters and audio interfacing devices. Radial’s latest release is a perfect example of these guiding principles.

The HDI Direct Box delivers studio-grade recordings anywhere with any instrument. The contents of the DI box may house complex circuity (including a Jensen transformer), but the outside controls are easy to use. In terms of knobs, we’re talking about Level, Color and Presence controls that allow you to go from pristine and clean to more amplifier-like distortion and saturation.

Elsewhere on the HDI Direct Box, there is a switch for a High Pass Filter. The three-position HPF switch enables players to clean up their sounds when using the Color control to add distortion. The lowest position means the HPF is turned off, the second position rolls off frequencies below 40Hz and the top position rolls off from 100Hz.

Last, but not least, the front of the HDI features a switch for engaging an onboard optical compressor. There is an LED light above the switch that allows you to monitor when gain reduction is happening. As for controlling the compressor, the bottom position means you’re in bypass mode and the top two positions apply smooth compression to the clean channel of the Color control. The upper position has a lower threshold than the middle setting.

As for the rear panel of the HDI, the direct box has a 1/4″ input and mono 3.5mm input for connecting your modular synthesizer rig. The outs on the unit include a processed output jack, XLR Mic Output and Line Output. There is also a 15dB pad button that reduces the signal level at the Line-Level XLR output.

Want to hear the Radial Engineering HDI Direct Box at work? We cut a down and dirty demo using the HDI to show how you can capture high-quality bass, guitar and synthesizer recordings.

«     |     »