Radial Engineering JD6 Six Channel Rack Mount D.I. User manual

Radial JD6
Six Channel Rack Mount D.I.
www.radialeng.com
User Guide
True to the Music
Radial Engineering Ltd.
1845 Kingsway Ave, Port Coquitlam BC V3C 0H3
Tel: [phone] • Email: [email protected]
Radial JD6 User Guide Part # R870 1045 00. Specications and appearance subject to
change without notice. Copyright © 2015 Radial Engineering Ltd. All rights reserved. / 11-2023

TABLE OF CONTENTS PAGE
Introduction ............................................................................................................................................. 2
Front Panel Features............................................................................................................................... 3
Rear Panel Connections ......................................................................................................................... 4
Using the JD6 ......................................................................................................................................... 4
Grounding Options for the System Engineer .......................................................................................... 5
Typical Stage Set-up Using the Radial JD6 ............................................................................................ 6
Specications and Block Diagram........................................................................................................... 7
Warranty Information ...............................................................................................................Back Cover
Congratulations on your purchase of the Radial JD6 multi-channel direct box. The JD6 is a world-class 19" rack-
mountable DI system that has been optimized for use with keyboards, guitars, and instruments of all types.
As there are many innovative features in the JD6, we recommend that you take a few minutes to read through this manual
in order to familiarize yourself with the design and features that are built in. Most importantly, the Radial JD6 features
internal grounding options that will be of particular interest to engineers when integrating the JD6 with keyboard racks.
Should you have a question or application in mind that is not covered in this manual, we invite you visit
www.radialeng.com to check the FAQ section for the latest updates.
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Radial Engineering Ltd. JD6 Six Channel DI User Guide
Radial JD6
User Guide

INTRODUCTION
The Radial JD6 is a 6-channel rackmount version of the highly successful Radial JDI direct box. Upon inspection you
will notice that channels 1 and 2 differ from channels 3 through 6. A ‘Swiss Army knife’ approach is introduced to allow
the 1st two channels on the JD6 to be problem solvers for stage and studio. Added features include a high frequency
lter to reduce noise, and a merge function to mix left & right keyboard outputs to mono. The other 4 channels address
basic DI requirements as normally required for keyboards, electronic drums and other audio sources.
As with all Radial direct boxes, the audio signal path is of utmost importance. The Radial JD6 is a passive direct box
and employs the nest Jensen™ audio transformers for absolute best performance. Each channel of the JD6 has been
provided with internal grounding switches to allow the system engineer to select between oating and chassis grounding
for maximum exibility.
Key features on the JD6 include switching jacks for channels 1 and 2 whereby the front jacks take priority over the
rear panel jacks. This is of particular importance in studio set-ups where the JD6 can act as a patch bay to quickly
recongure the signal path.
Like all Radial products, the JD6 is designed to handle the harshest touring environments. Welded 14 gauge steel
construction, baked enamel nish, high-cycle rate switches and glass-lled high-impact polymer connectors with
nickel silver contacts combine for maximum durability. The Radial JD6 is supported with a 3-year limited warranty.
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Radial Engineering Ltd. JD6 Six Channel DI User Guide
True to the Music

1. –15dB Pad: All channels on the Radial JD6 feature a -15dB pad to reduce the level coming from high output sources.
2. 8kHzlter:Channels 1 & 2 feature a gentle low-pass lter that rolls off highs at 8kHz. This is designed to remove
hiss from noisy source devices. To engage the lter, the pad must also be depressed.
3. 180ºpolarityreverse:The 180º polarity reverse is used to reverse the polarity (sometimes called absolute phase
reverse) at the XLR by ipping pin-2 and pin-3. This is used when interfacing with older equipment that was made
before the AES pin-2 standard was adopted. It can also be used in a creative way when combining direct and mic’d
sources.
4. Groundlift:The ground lift switch is used to disconnect pin-1 at the XLR output to help eliminate hum and buzz
caused by ground loops. Lifting the XLR ground connection presumes you intend to ground the JD6 at the input.
 NOTE:InsidetheJD6areindividualchassisgroundliftswitches.Thesearefactorysettooatthusproviding
isolationbetweenadjacentchannelsandprovide100%oatingcircuitsasifusing6separatedirectboxes.
This is detailed further in the manual.
5. Input connector: For maximum exibility, the Radial JD6 features both front and rear ¼” input and thru-put
connectors on channels 1 and 2. feature ‘priority switching jacks’ on the front panel. This means that when the
channels are normally connected using the rear panel jacks, the front panel jacks will divert the input giving these
priority, thus temporarily disconnecting the rear jacks until such time as the front panel input jacks are removed.
This is of particular advantage in a studio where the JD6 may be ‘wired’ to a patch bay for the keyboards. To patch
in a bass, one would simply plug into the channel-1 front panel ¼" jack and start recording.
6. Thru-putconnector: As with all direct boxes, the JD6 is outtted with a thru connector on each channel. This is
used to pass the direct signal directly thru to the instrument amplier. On channels 1 & 2, these are duplicated on
the front and the rear of the unit and feature switching jacks with front panel priority. Normally, the thru will be
connected on the rear panel. By inserting a jack into the front panel THRU connector, the signal will be diverted to
the front jack and disconnect the rear connection.
7. Mergefunction:Channels 1 & 2 also feature a function called Merge. When this switch is depressed, it turns the
Input and Thru-put connections into a ‘left and right’ mix to mono at the XLR output. This passive (resistor) mix
or summing function is a real helper when there are insufcient snake or mixer channels to handle over-abundant
channel feeds in some keyboard set-ups. Depressing the merge switch affects both the front and rear jacks.
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Radial Engineering Ltd. JD6 Six Channel DI User Guide
FRONT PANEL FEATURES
True to the Music
1 2 3 4 5 6 7

REAR PANEL CONNECTIONS
Upon rst inspection, the rear panel connections appear to be identical for all channels. Although true, it should be
noted that channels 1 and 2 employ switching jacks with front panel priority. This means that these channels will work
exactly the same as the others unless the front panel jacks are employed. This would of course divert the input from
the rear to the front as the front input jacks have been given priority.
All channels feature an input connector that is connected to the source and a thru connector that is normally connected to
the keyboard player’s personal mixer. The XLR output employs the AES standard with pin-1 ground and pin-2 hot. This
is isolated using a Jensen JT-DBE transformer and is connected to the mixer. The XLR output provides a transformer
isolated mic-level signal that can drive cables up to 300 feet (100 meters) without introducing noise.
It is important to note that the output of the JD6 be microphone level so that it can run along side mic signals without
introducing crosstalk or distortion when passing through typical mic splitters. As such, the output of the JD6 must be
connected to the mic input on a mixer or to a microphone preamplier in order to properly match your levels and impedance.
Doing so will provide optimum sound quality and the best overall performance.
USING THE JD6
Before connecting the JD6 to your system, ensure all levels are turned off so that you do not cause connection pops in
your system. All switches should be in the OUT position when setting up the system. The JD6 is completely passive and
therefore requires no power. Just plug and play. Having 48V phantom on to power condenser microphones or active direct
boxes will not harm the JD6.
On each channel, connect the source instrument to the input, your instrument amplier or personal mixer to the thru-put and
the XLR output to the main house or recording mixer. If noise is encountered, try lifting the ground. If the level seems high on
a particular channel, engage the -15dB pad.
When recording a direct feed from your instrument as well as a the feed from a microphone placed on an amplier, try
reversing the polarity. Should you need to sum a stereo source down to mono, connect the left and right outputs of your
device to the input and thru connectors of channel 1 or 2 and press the merge switch.
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Radial Engineering Ltd. JD6 Six Channel DI User Guide
True to the Music

GROUNDING OPTIONS
FOR THE SYSTEM ENGINEER
For pro-touring, the Radial JD6 is outtted with some
helpful grounding schemes. This allows the system
integrator, studio designer or keyboard technician to use
several options to best adapt to their designs for safe and
noise-free performance.
As noted earlier, all JD6 channels feature a separate XLR
pin-1 ground lift for each channel. It is important to note
that each channel of the JD6 is also 100% isolated from
each other to eliminate crosstalk and potential ground
problems. This is why all of the input jacks are isolated.
Inside the JD6 are six additional ground switches (g. 1)
that allow the system engineer to bond the circuit ground to
the chassis. Normally, each channel of the JD6 is ‘oating’
whereby each channel acts as if it were a separate or a
stand-alone direct box. Some system engineers prefer to set-
up alternate ground schemes such as ‘star grounds’ whereby
a single ground point is employed and all channel grounds
are directed to this point. These switches are factory set in
the oating position but may be changed by simply opening
up the JD6 and depressing the chassis ground switch. A
ground lug on the rear panel (g. 2) would then be used to
bond the JD6 chassis to the rack or a ground bus.
As an added feature, channel-1 employs a side access
ground switch (g. 3) for system engineers that employs a
single audio channel for chassis ground. This is activated
using a small screwdriver.
NOTE: Chassis grounding is usually not required
with the Radial JD6 because of the isolating nature
ofthedeviceandtheextensivegroundplanethatis
employed.Unlessyouareaqualiedsystemengineer,we
recommendthatthesebeleftinthefactorysetposition.As
such,changingthesehaspurposelybeenmadedifcult.
Fig. 1 Internal ground switch on each chan-
nel is factory set to 'oat'
Fig. 3 Channel 1 side access switch connects
chassis ground to pin-1. Factory set 'out' to
'oat'
Fig. 2 A convenient chassis ground is pro-
vided to allow alternate ground schemes
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Radial Engineering Ltd. JD6 Six Channel DI User Guide
True to the Music

6
True to the Music
TYPICALSTAGESET-UPUSINGTHERADIALJD6
The Radial JD6 may be used in a variety of congurations. This common set-up for stage use shows a computer with
an audio interface connected to channels 1 & 2, keyboards to channels 3 & 4 and sound modules to channels 5 & 6.
SWITCHING JACKS SWITCHING JACKS
FRONT PANEL HAS PRIORITY FRONT PANEL HAS PRIORITY
Balanced outputs to house mixer
House mixing console
From JD6 to musician’s
personal mixer
Samplers
Keyboards
Computer
To Radial JD6 Direct Box
Typical Block Diagram
using Radial JD6 in concert setting
Radial Engineering Ltd. JD6 Six Channel DI User Guide

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Radial Engineering Ltd. JD6 Six Channel DI User Guide
True to the Music
SPECIFICATIONS
Audio circuit type: .............................................................................................................Passive, transformer based
Number of channels: ................................................................................................................................Six channels
Frequency response: ............................................................................................................ 20Hz ~ 20KHz (± 0.2dB)
Dynamic range: .................................................................................................................................................135dB
Maximum input: ...................................................................................................................................+21dB @ 20Hz
Total harmonic distortion: .................................................................................... 0.05% from 20Hz ~ 20kHz @-10dB
Phase deviation: ................................................................................................................ 0.3° @ 100Hz; 3° @ 20Hz
Input impedance: .................................................................................................................. 140k Ohms, unbalanced
Output impedance: ..................................................................................................................... 150 Ohms, balanced
Transformer:....................................................................................................................... Jensen JT-DBE, 12:1 ratio
Shield: ........................................................................................................Mu-metal can with internal Faraday shield
Input pad: ...........................................................................................................................................................-15dB
Merge: .......................................................................................... Sums left & right sources to mono (ch. 1 & 2 only)
180° polarity reverse: .............................................................................................................. Inverts absolute phase
Ground lift: ................................................................................................................Disconnects pin-1 at XLR output
XLR conguration: ................................................................................................................AES standard (pin-2 hot)
Connectors (Channels 1-6): ................................................................................................. 1/4" in & thru, XLR-M out
Construction: ......................................................................................................14 gauge steel chassis & outer shell
Finish:.......................................................................................................................................... Durable powder coat
Size (W x H x D):.........................................................................................483 x 44.5 x 159mm (19" x 1.75" x 6.25")
Weight: ...................................................................................................................................................3.6 kg (8 lbs.)
Shipping Size (W x H x D):.................................................................... 260 x 114 x 568mm (10.25" x 4.50" x 22.37")
Shipping Weight: .................................................................................................................................3.7 kg (8.15 lbs)
Power: ..............................................................................................................................Passive, no power required
Conditions: .................................................................................For use in dry locations only between 5°C and 40°C
Warranty: ........................................................................................................................... Radial 3-year, transferable
Specications are subject to change without notice.

THREE YEAR TRANSFERABLE LIMITED WARRANTY
RADIAL ENGINEERING LTD. (“Radial”) warrants this product to be free from defects in
material and workmanship and will remedy any such defects free of charge according
to the terms of this warranty. Radial will repair or replace (at its option) any defective
component(s) of this product (excluding nish and wear and tear on components under
normal use) for a period of three (3) years from the original date of purchase. In the event
that a particular product is no longer available, Radial reserves the right to replace the
product with a similar product of equal or greater value. In the unlikely event that a defect
is uncovered, please call 604-942-1001 or email [email protected] to obtain a RA
number (Return Authorization number) before the 3 year warranty period expires. The
product must be returned prepaid in the original shipping container (or equivalent) to
Radial or to an authorized Radial repair center and you must assume the risk of loss or
damage. A copy of the original invoice showing date of purchase and the dealer name
must accompany any request for work to be performed under this limited and transfer-
able warranty. This warranty shall not apply if the product has been damaged due to
abuse, misuse, misapplication, accident or as a result of service or modication by any
other than an authorized Radial repair center.
THERE ARE NO EXPRESSED WARRANTIES OTHER THAN THOSE ON THE FACE
HEREOF AND DESCRIBED ABOVE. NO WARRANTIES WHETHER EXPRESSED
OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE SHALL EXTEND
BEYOND THE RESPECTIVE WARRANTY PERIOD DESCRIBED ABOVE OF THREE
YEARS. RADIAL SHALL NOT BE RESPONSIBLE OR LIABLE FOR ANY SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSS ARISING FROM THE USE
OF THIS PRODUCT. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS,
AND YOU MAY ALSO HAVE OTHER RIGHTS, WHICH MAY VARY DEPENDING ON
WHERE YOU LIVE AND WHERE THE PRODUCT WAS PURCHASED.
www.radialeng.com
Radial Engineering Ltd.
1845 Kingsway Ave, Port Coquitlam BC V3C 0H3
Tel: [phone] • Email: [email protected]
Radial JD6 User Guide Part # R870 1045 00. Specications and appearance subject to
change without notice. Copyright © 2015 Radial Engineering Ltd. All rights reserved. / 11-2023
To meet the requirements of California Proposition 65, it is our responsibility to inform you of the following:
WARNING: This product contains chemicals known to the State of California to cause
cancer, birth defects or other reproductive harm.
Please take proper care when handling and consult local government regulations before discarding.