Recording - May 2016 - 42

BY ALEX HAWLEY

Radial Engineering features a wide variety of gear built for both
the studio and stage. Based in Vancouver, Radial is widely known
for its line of great-sounding and nearly indestructible DI boxes,
with products built for any application or I/O situation imaginable.
Radial is also home to other products such as interfaces, guitar amp attenuators, 500 Series modules, and reamping tools,
just to name a few. Today we will be taking a look at the
newest generation of Radial's flagship active DI, The JDV. The
JDV mk5 is a Class-A active direct box and preamplifier, armed
with tons of useful features.
Origins
The first generation JDV originated in the 1980s, traced back
to renowned studio designer John Vrtacic. Vrtacic's custommade direct box stood apart from the others, quickly becoming

Radial Engineering JDV Mk5

The Drag control for Channel A adjusts
the load from 1MΩ down to 10kΩ.
Truly a "Super Direct Box", this DI lets you add miked signals with ease Turning the control clockwise will add air
and make the tone sound brighter.
known for capturing amazing bass tones with an extremely accu- Turning the control completely counterclockwise will round off
the tone, making it sound warmer and slightly darker. We'll talk
rate signal. Vrtacic accomplished this by discovering a way to
more about Drag in a moment.
buffer the direct signal without the use of negative feedback.
Channel B has, in place of the Drag Control, two different load
After a shootout between some of the top active DI boxes on
the market, Vrtacic's custom-made design had an overwhelming settings-220KΩ or 10MΩ. The 10MΩ load setting is intended for
response. Radial quickly reached out in an attempt to purchase piezo transducers. Elevating the impedance with a piezo dramatically widens the frequency response and smooths out the tone.
the design. It worked-and this is how the first generation JDV
If you are using two separate instruments with the JDV, you
(V for Vrtacic) came to be.
can switch between channels A and B via front panel switch
Overview
or optional footswitch. The currently selected channel will be
indicated from an LED on the front panel.
The JDV Mk5 is very well designed. An arched handle that
Both channels come with green and red signal-present and
sweeps the top of the unit makes it easy to carry, and the metal
overload LEDs, and a highpass filter ranging from 5 Hz to
casing extends over the pots and switches for extra protection
(a common Radial design feature). There are optional additions 500 Hz. Also on the front panel is an LED for the Mute feature, which is available via the optional JR-2 footswitch.
to rackmount the unit, should your JDV Mk5 want to live in a
Phantom power for channel A has a front-panel indicator
rack rather than on a tabletop or amp. Overall, the JDV Mk5 is
pleasing both aesthetically and practically, and is a rare breed light and a recessed button on the side panel. Also on the side
panel are recessed controls to transformer-isolate the Aux
of DI units that excels in both live and studio situations.
(Thru) output if desired, and to turn on Blend. The rear panel
The JDV mk5 is a dual-input DI, mic preamp, and phase
has recessed controls pertaining to the XLR output-180º
adjustment tool. The front end on the JDV features 100% discrete electronics, and a unique Class-A design using zero nega- phase flip, ground lift, transformer isolation, and a +20 dB
switch (see below). Both transformers are made by Jensen.
tive feedback to buffer the signal. This creates an extremely
accurate signal, without adding any coloration or artifacts of
Blend it and Phaze it
any kind. The JDV Mk5 also comes armed with Radial's wellCombining both inputs with the Blend function can create a
known Drag control, which allows you to adjust the input
impedance to match any pickup. The output is handled by a sin- very full, well-rounded tone. Once you've adjusted relative levels on the inputs, the built-in Phazer phase adjustment tool
gle XLR out, armed with isolated Jensen transformers, and a
allows you to accurately time-align both channels for use on a
new +20 dB feature to send out line-level signal-eliminating
single instrument, such as a pickup and a condenser microthe need to run the JDV Mk5 into a mic preamp at the mixer.
phone on an acoustic guitar. Using a pickup in conjunction
A walkthrough
with another microphone can produce a much more rich and
The rear panel has two instrument inputs, a TRS input, a Thru balanced tone than just using a pickup alone.
The Phazer really opens up some flexibility when using a twofor your amp, a Tuner output, and a footswitch input, all on
1
/4", and an XLR output, plus a 4-pin socket for the external
input setup on stage. The placement of the microphone may change
power supply.
from gig to gig, but a quick adjust with the phase tool can ensure
Input A can accommodate anything from a magnetic pickup to that everything sounds full and vibrant, even after getting folded into
a condenser microphone (yes, with 48V phantom power!), the
the single XLR output. When working in a home studio with limited
mic preamp real estate, the ability to blend both signals then output
latter using a dedicated balanced 1/4" TRS microphone input.
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RECORDING MAY 2016

Table of Contents for the Digital Edition of Recording - May 2016