Radi J-ISO User manual

www.radialeng.com
Radial Engineering Ltd.
1845 Kingsway Ave, Port Coquitlam BC V3C 1S9
Tel: [phone] • Fax: [phone]
Email: [email protected]
J•ISO | Pro-ISO
Users Guide
True to the Music
Radial J•ISO and ProISO users guide V1.2 - Part #: R870 1220 10 / 07-2023
Subject to change without notice
+4dB Balanced to -10dB Unbalanced
Stereo Signal Conversion Tool
®

3
INPUT PANEL
1. XLR INPUT for balanced,
low-impedance, +4dB line-level
signals.
2. Ground lift disconnects the
signal ground to eliminate buzz
and hum caused by ground loops.
3. Secondary Ground Lift used
for instances where two separate
devices are connected to the
outputs.
OUTPUT PANEL
4. Output Level provides signal
attenuation to prevent clipping.
5. 3.5mm TRS output connection
for stereo -10dB devices such as
portable recording units.
6. RCA Phono left and right stereo
outputs for -10dB consumer audio
electronics.
7. ¼" TS left and right stereo
outputs for high-impedance audio
electronics.
CONSTRUCTION
8. Bookend design 14 gauge steel
outer shell creates protective zone
around connectors and switches.
9. I-beam enclosure eliminates
stress that could torque the PC
board and cause solder joint failure.
10. PCB mounted switches are
high-cycle rated for long life.
11. Jensen (J•ISO) and Radial
(Pro-ISO) transformers offer
outstanding audio performance.
12. Military-grade double-sided
PCB with plated through-holes is
bolted to welded steel stando󰀨s.
13. Full-bottom no-slip pad This
provides electrical isolation and
plenty of "stay-put" friction.
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J•ISO / Pro-ISO User Guide
Radial Engineering Ltd.
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A major benet of using transformers is the elimination of noise caused by ground
loops. The transformer isolates the devices connected to it by decoupling the
signal ground between the input and output. This isolation e󰀨ectively breaks
ground loops between devices and blocks hum and buzz.
GROUND LIFT
To make grounding as exible as possible, both units feature a ground LIFT
switch. When in the lifted position, the input signal ground is decoupled through
the audio transformer and isolated from the output signal ground. If you hear
hum or buzz, try depressing the LIFT switch and use the position that produces
the least noise.
LEVEL CONTROL
The J•ISO and Pro-ISO feature a variable audio level control that can be called
upon to attenuate hot signals and prevent the inputs of the destination audio
device from clipping.
RCA & 3.5mm JACKS
Consumer audio electronics such as mobile recorders connect directly using the
3.5mm and RCA inputs, thus eliminating the need for cumbersome adapters.
Two ¼" phone jacks are also provided. All output jacks are wired in parallel and
can be used to split the stereo signal and send it to a second audio device. You
can connect a mixer to the RCA outputs and a mobile recording device to the
3.5mm phone jack and record the signal on both. Keep in mind that the source
audio level may need to be increased to drive the additional load that a second
device presents.
SECONDARY GROUND LIFT
A secondary recessed ground lift switch is accessed through a small hole in the
side of the enclosure. This switch disconnects the common ground connection
between the left and right output jacks. For normal stereo operation with one
audio device connected to the outputs, this switch can be set either open (pushed
“out”) or closed (pushed “in”).
However, if you intend to connect a second device or use the J•ISO in dual
mono mode (where the left and right output channels drive two separate audio
devices) there may be a gain in noise performance by depressing this switch. If
you hear hum or buzz while operating with two devices connected, try toggling
the recessed switch and use the setting that produces the least noise.
J•ISO / Pro-ISO User Guide
Radial Engineering Ltd.

CONGRATULATIONS on your purchase of the Radial J•ISO or Pro-ISO passive
signal conversion tools. As with all Radial products the J•ISO and Pro-ISO
are easy to use and ensure the best audio quality. This short manual contains
all the information you need to start using the tools right away. For more
information on the J•ISO, Pro-ISO and other Radial products, visit our web site
at www.radialeng.com. The Radial J•ISO and Pro-ISO are thoughtfully designed
and useful devices that will provide you with years of reliable service. Enjoy!
INTRODUCTION
The Radial J•ISO and Pro-ISO are two channel line-level signal conversion tools
with transformer isolation to prevent noise from ground loops. Both units are
identical except for the audio transformers. The J•ISO features two premium
Jensen audio transformers. The Pro-ISO uses high quality Radial transformers.
Both units convert +4dB balanced signals to -10dB unbalanced with optimum
signal-to-noise and signal transfer quality.
These devices allow you to connect professional balanced audio gear to
consumer unbalanced. In addition to standard RCA stereo outputs, both units
are equipped with ¼" instrument and 3.5mm jacks, allowing virtually any -10dB
audio device to be connected without adapters cables.
For instance, the J•ISO and Pro-ISO are great tools to interface a pro mixing
console or high-end microphone preamp a portable recorder or camera to
capture the house mix.
J•ISO / Pro-ISO User Guide
Radial Engineering Ltd.
The J•ISO and Pro-ISO do not require any power to operate. They are extremely
portable and plug-and-play easy to use. The circuit is 100% passive and will
not add any noise to the signal. The rugged construction is compact enough to
take anywhere and dependable for service out on the road.
XLR INPUTS
These inputs are intended for professional audio equipment with a balanced
+4dB line output. The Pro-ISO uses the AES standard XLR pin-out where PIN-2
is hot (+) and PIN-3 cold (-).
AUDIO TRANSFORMERS
A pair of audio transformers converts the low-impedance balanced +4dB
source signal into a high-impedance, unbalanced output. Jensen and Radial
transformers are exceptional for their linear frequency response and ability to
handle high input levels without distortion.
+4dB Balanced -10dB Unbalanced

J-RAK AND J-CLAMP
The optional J-RAK is a high density
rackshelf for Radial DI’s and splitters. It’s
a 2RU rack chassis that allows up to 8
Radial devices in one neat high density
19" package. The DI’s can be mounted
with either the input side or output side
facing the front. Ideal for studio or touring.
Constructed of 14 gauge steel with a baked
enamel nish.
The optional J-CLAMP can mount a single
Radial device to virtually any surface.
Perfect for hiding away inside racks, on
podiums or under tables. Constructed of
14 gauge steel with a baked enamel nish.
USING THE Pro-ISO
All Radial Engineering products are designed for simple, straight-forward use.
However, attention taken during set-up will ensure success. Before connecting
ensure the sound system is turned o󰀨 and all levels are set to zero. This will
avoid any pops in the sound system that could cause damage to speakers,
headphones or your ears.
Conrm the recessed LEVEL control is set at its maximum clockwise position
and the LIFT switch is pushed inward. The Pro-ISO is completely passive and
does not require a power supply of any kind to operate.
1. Connect the balanced +4dB audio source to the XLR inputs using balanced
cables.
2. Use unbalanced cables to connect the outputs to the destination audio device.
Unbalanced cables should be kept under 20 feet in length to maintain the
best delity.
3. To conrm audio quality, you should monitor the destination audio device with
a set of headphones or a stereo loudspeaker system.
4. Turn the source audio level up slowly and listen for noise. In the event you
encounter hum or buzz, simply depress the ground lift switch.
5. Bring the source audio up to unity-gain. If the sound is distorted (clipping) turn
the LEVEL control down. You are now set to go!
J•ISO / Pro-ISO User Guide
Radial Engineering Ltd.

RADIAL ENGINEERING 3 YEAR 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. To make a request or claim under this limited warranty, 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 warranty. This limited 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 RESPON-
SIBLE 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.
SPECIFICATIONS
Pro-ISO J•ISO
Freq. response 20Hz to 18kHz (+0dB, -3dB) 20Hz to 20kHz (+0dB, -1.5dB)
THD @ 1k 0.005% @ 1kHz 0.001% @ 1kHz
Stereo Inputs Balanced, low-Z, +4dB line-level, female XLR, pin-2 hot
Outputs Unbalanced, high-Z, -10dB line-level, RCA, ¼", and 3.5mm TRS
Power None, completely passive
Size 3.3" x 5" x 2"
Weight 1.55 lbs
J•ISO / Pro-ISO User Guide
Radial Engineering Ltd.
®
www.radialeng.com