Radial Engineering JDX 500 Reactor User Manual

True to the Music

www.radialeng.com

®

True to the Music

®

User Guide

JDX™ 500 Reactor

Amplifier Direct Box & Cabinet Emulator

500 Series Module

www.radialeng.com

Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam
British Columbia, Canada, V3C 5M5
tel: [phone] • fax: [phone]
email: [e-mail]

WARNING NOTICE TO USER!

The Radial JDX 500 is not a load box. This means that if you are using it with a guitar
amplifi er it must be connected to a speaker cabinet or some type of load box. Failure
to do so could result in damaging the JDX and your amplifi er which of course would not
be covered under warranty. Always ensure you have proper cables and connections
have been checked. We recommend using high quality 12 gauge speaker cables.

Because the JDX 500 can also be used as a direct input from a guitar, we have
instituted a slow fl ashing LED to let you know when you are in this mode. This safety
measure reminds you that you should not connect a guitar amplifi er output to the JDX
when in guitar mode as this may damage the JDX.

Although preventative safety measures have been designed into Radial 500 series
products we strictly advise against hot-swapping modules or plugging and
unplugging them when the Workhorse or other 500 series rack is powered on. Hot
swapping can cause connection sparks at the card-edge connector that could send
damaging transients to other equipment. This also greatly reduces the life span of the
contacts. Damage due to hot swapping is not covered under warranty. There are no
user serviceable parts inside.

Radial® JDX™ 500 Reactor User Guide

Table of Contents ......................................................Page

Feature Set .................................................................... 1

Overview ........................................................................ 2

Function Details ............................................................. 4

Getting Started ............................................................... 5

Amp Mode ...................................................................... 6

Guitar Mode ................................................................... 7

Re-amping and Other Applications ................................ 8

Specifi cations ................................................................. 9

Block Diagram ................................................................ 9

Warranty ........................................................... Back cover

Congratulations and thank you for purchasing the Radial JDX 500 Reactor module. The
JDX is a unique 500 series amplifi er interface designed to capture the dynamic relationship
between an amplifi er and speaker cabinet while also offering direct instrument recording with
active speaker cabinet emulation.

This manual describes installing and operating your JDX 500 in the Radial Workhorse or
other 500 series module power racks. To take full advantage of the unique features that
have been incorporated into the JDX 500, please read through this manual before using
it. This user guide will give you a broader sense of the module’s capabilities. If you have
questions that are not covered in this manual, please visit the FAQ section on our website.
This is where we post answers to questions from users. If you cannot fi nd the answer to your
question please feel free to send an email to [e-mail] and we will do our very
best to respond as quickly as possible.

The JDX 500, one small step for audio engineering, one huge leap for tone fanatics!

True to the Music

®

Radial Engineering Ltd.

JDX 500 Module

FEATURE SET

1. 180º REVERSE - Inverts the signal polarity
between 0° and 180°.

2. LIFT - Ground lift switch works with the
transformer isolation to help eliminate hum
and buzz caused by ground loops.

3. LPF TONE SHIFT - Low pass fi lter control,
rolls off the high end to tame the aggressive
edge from overly bright sounding amps.

4. LF-EXT - Low frequency extension, lowers
the bass frequency response to emulate the
sound of a 15” speaker for added bass.

5. GUITAR - Toggles the front panel 1/4” jacks
between “amp mode” and “guitar mode”.
When set to “guitar mode” (inward position)
instruments may be connected directly
to the 1/4” HEAD jack. The LED indicator
fl ashes when “guitar mode” is engaged.
Do not connect an amplifi er when the LED
is fl ashing. Read the user warning notice

before using this feature.

6. 300W - Reduces the input sensitivity to allow
high-power guitar and bass amps to be used
with the JDX.

7. 1/4” HEAD JACK - Used to connect amps or
instruments depending on the position of the
GUITAR switch. When the JDX is in “amp
mode” this jack connects the speaker output
of an amplifi er. When the JDX is set to “guitar
mode” instrument may be connected directly
to this jack. Read the user warning notice

before using this feature.

8. 1/4” SPEAKER JACK - Used to connect a
speaker cabinet when JDX is used with
an amplifi er. The JDX is not a load box.

Therefore, it must be connected to a
speaker or load box when used with a
guitar amp.

9. OMNIPORT - When installed in the Radial
Workhorse rack you will have access to the
Omniport ¼” TRS jack. The JDX Omniport
is an alternative output set up as a balanced
mic-level direct box to feed a microphone
preamp, snake system or mixing console in
a live touring setup.

8

7

1

4

3

2

6

5

Rear Panel

1

9

Radial Engineering Ltd.

JDX 500 Module

True to the Music

®

2

OVERVIEW

The Radial JDX 500 is a 500 series module designed to bring the sound of a guitar amplifi er
into the recording system without having to necessarily set up microphones or amplifi ers. In
other words, it is designed as a quick production tool for professionals who make music and
record.

Inside the JDX are two different circuits: The fi rst is a reactive load that captures the sound
of the head and the back electro-magnetic impulse from the loudspeaker. The second is
a series of band-pass fi lters that shape the tone to create the 4x12 cabinet emulation. To
address the problem of overly bright amplifi ers, the front panel is equipped with a variable
low-pass fi lter designed to gently remove high end.

There are two basic ways to use the JDX: For the ultimate tone, the JDX can be connected in
‘amp-mode’ where it is placed between a guitar head and cabinet to capture both the sound
of the amplifi er and the reactive load of the cabinet.

Alternately, the JDX can be used in ‘guitar mode’ whereby the amplifi er and cabinet are not
used. Instead, the guitar is connected directly to the JDX, via some effect pedals, to take full
advantage of the advanced multistage speaker emulation fi ltering. If you have ever tried to
record a guitar through an overdrive pedal directly to the recorder you know how unpleasant
it can sound. The JDX fi ltering circuit takes the harshness away by emulating the response
of a speaker cabinet. The variable low-pass fi lter gives you extra control to further shape the
tone. Using the JDX in guitar mode is a great approach to laying down quick tracks when
writing. Simply connect your guitar to some pedals then into the JDX and you are set to go.

You can also use the JDX as an analogue fi lter to warm up tracks by sending a pre-recorded
track into the JDX via the XLR input. This approach applies to more than just guitar tracks.
Sending a synth or bass through the JDX can add mid range punch that can make a track
stand out. As always… there are no rules, only guidelines. Have fun. Experiment!