New Music Gear Monday: Radial Engineering HDI High-Definition Direct Box

If you’ve been reading this blog for a while you know that I’m a big fan of all products from Radial Engineering, but their direct boxes in particular. The JDI has been a long-time a standard for both studio and live and with good reason. It’s built like a tank and will last forever, and it simply sounds better than anything else even near the price range (especially for bass). Now the company has taken that concept to the next level with its new HDI high-definition direct box.

What makes the HDI different from Radial’s other DIs is that it can be as clean as you want it, but it also has the ability to add both color and some pleasing saturation as well. This is because the box actually has 2 signal paths – a clean one, and another using guitar amp-style topology and a specially designed Jensen output transformer to add some warm saturation if needed.

There are 3 basic controls on the front of the HDI – Level, Color, and Presence. The Color control allows blending of the signal from ultra-clean operation on one side to amp-like distortion and warm transformer saturation on the other. The Level control allows the HDI to accommodate a wide range of input sources while also enabling increased drive signal to the internal circuitry for more exaggerated coloration if required. The Presence control provides an emphasis on the high and high-mid frequencies so you can dial in just the right amount of bite for the signal to cut through a mix.   

Aside from the three main controls, the HDI also includes a VU meter, a Hi-Z switch that approximates the Hi and Lo inputs on a vintage amplifier, and a single-control Opto compressor which allows for smooth and natural peak reduction of the input signal. A 3-position high-pass filter rolls off any excessive low end created when pushing the HDI into distortion, and a ground lift switch rounds out the front panel controls and helps eliminate any hum and buzz that might be present. 

Inputs for the HDI are provided on front and rear panel ¼” jacks along with a Thru connection for an amplifier. A 3.5mm mono Synth Input is included for easy connection to modular synthesizers (that’s pretty cool). Transformer-isolated mic and line-level XLR outputs provide the direct connection to mic preamps and recording interfaces, along with a ¼” Processed Output for feeding the affected signal to a guitar amp or instrument effects units.  

This is a box that takes direct injection to the next level, offering the color and saturation that we’d normally have to add after the fact right there at the source.

The HDI was actually introduced at the NAMM show in January (which now seems so far in the past) but it’s just now shipping. It retails for $799. You can find out more about the Radial HDI on its dedicated page. There’s a bit more in the video below.

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