JDV™ Using & Applications

This short guide is written for those who are experienced with pro-audio and direct boxes. Complete details about the many features built into the JDV active direct box and information about connecting it to your system can be found in the user guide (PDF download).

The Radial JDV is a high performance direct box that is equally effective for studio and stage. As a direct box, it simultaneously takes a high impedance instrument level and splits it off to drive the stage amplifier and tuner, while providing a mic balanced XLR output to feed a mic preamp or mixing console. The unity gain design coupled with exceptional signal handling means that what you put in, you will get out! This allows the JDV to be used with practically any instrument or signal source.



As with all electronic products, always ensure the volume levels are turned down or equipment turned off to avoid hook-up and/or turn on transients that could damage loudspeakers or more sensitive electronics. Connect the power supply to the JDV. There is no on-off switch. As soon as the power supply is connected, the JDV will turn on. Allow the JDV to warm up as electronic circuits tend to sound best when they reach their ambient working temperature.

Connect the instrument into input-A. Make sure the instrument selector switch is in the out position to select input-A. Connect the thru to the amplifier and the XLR output to the mic input of the console or preamp. Note that direct boxes are designed to produce a mic level signal to match the output of a typical microphone. Turn up the levels slowly to test. If you hear any hum or buzz, depress the ground lift switch.

JDV Connections
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Features and Functions



The JDV is equipped with two filters: a lo-cut and a hi-cut. The lo-cut is a high-pass filter that is designed to gently roll bass frequencies off to eliminate resonance with acoustic instruments or reduce mud when recording. Bass frequencies contain much more energy than high frequencies and attenuating them when not needed will help reduce distortion and clean up the sound of the mix. The hi-cut is a low-pass filter designed to eliminate hiss and attenuate buzz from older equipment that may sound great, but may not be all that well designed.


Drag Control

When Drag Control is set to off, the input impedance automatically reverts to 4meg-ohms for use with piezo transducers. When Drag Control is turned on, this allows you to vary the input impedance from 10kOhms to 1 meg-Ohms to optimize the impedance for magnetic pickups. Start by setting the Drag Control to 12 o'clock then listen. By turning the dial counter-clockwise, the tone will darken while clockwise, you will hear added greater harmonics. Simply use your ears to dial in the sound that suits the instrument.


Signal Distribution: Using More than One Amp

The JDV is equipped with a variety of outputs for maximum flexibility. This enables you to connect a tuner, stage amp, effects device, drive a secondary amp and even send a signal to another DI box if you so desire. Keep in mind that the JDV's transformerless design does not make provisions for isolated outputs. To avoid hum and buzz or potential electrical shock, always connect your amps and effects to the same power bar.

JDV unbalanced connection jacks.

Basic Live Setup - Bass to Amp to PA System

Basic Live Setup with JDV - Bass to Amp to PA System

The JDV's dual inputs make it easy to select between two instruments and send the signal to the instrument amp on stage, guitar tuner and effects. Then send the XLR out to the PA system for the most natural tone ever!


Studio Setup - Two Guitar Amps and a Tuner

JDV Studio Setup - Two Guitar Amps and a Tuner

The JDV's four outputs can be used to drive multiple amps, effects and a tuner to create rich textures and new tones. Adjust the Drag Control to record the ultimate clean track and then Reamp as needed.


Acoustic Guitar on Stage - PA and Acoustic Amp

JDV Acoustic Guitar on Stage - PA and Acoustic Amp

On stage, the JDV is the perfect interface for active or passive acoustic instruments. Dual inputs lets you switch between instruments while the JDV feeds your stage amp and the PA at the same time!