Twin-Iso Two Channel Line Level Isolator

Product Information

Radial Twin-Iso

The Radial Twin-Iso is a stereo (dual mono) line-level isolator
designed to isolate audio equipment and eliminate troublesome noise
caused by ground loops. It employs two high-performance Jensen
isolation transformers to ensure the best signal transfer without
artifacts or distortion. The Twin-Iso is made with 14 gauge steel
and features an internal welded I-beam frame for maximum rigidity.
It is built to withstand even the most abusive touring
environments.

The Twin-Iso is a versatile device that can be used for
sub-mixing multiple consoles, isolating amplifier distribution
racks, connecting remote speaker towers, and eliminating ground
loop problems when equipment needs to be connected to alternate
power sources. It provides electrical isolation between two
line-level devices, such as mixing consoles, remote speakers,
crossovers, and amplifier racks.

The Twin-Iso is equipped with two XLR inputs and two XLR
outputs. Each channel is 100% isolated from the other, allowing two
different audio sources to use the Twin-Iso simultaneously. The
transformers used in the Twin-Iso are of high quality and can
handle high signal levels without saturation or introducing phase
distortion or group delay.

Product Usage Instructions

Step 1: Connecting the Radial Twin-Iso

1. Connect the audio source to be isolated to one of the XLR
inputs on the Twin-Iso.

2. Connect the destination device to one of the XLR outputs on
the Twin-Iso.

3. If needed, repeat steps 1 and 2 for the second channel of the
Twin-Iso.

Step 2: Ground Loop Elimination

If you are experiencing ground loop noise in your audio system,
follow these steps:

1. Ensure that all devices in the audio chain are properly
grounded.

2. Connect the Twin-Iso between the source and destination
devices that are causing the ground loop noise.

3. The Twin-Iso will electrically isolate the devices,
eliminating the ground loop noise.

Step 3: Adjusting Signal Levels

The Twin-Iso is designed for +4dB professional line-level
signals. However, the transformers can handle over 20dB without
choking. Adjust the signal levels of the connected devices
accordingly to achieve the desired audio output.

Step 4: Enjoying Problem-Free Connectivity

The Radial Twin-Iso is built to provide years of problem-solving
connectivity. Enjoy the improved audio quality and noise-free
performance that the Twin-Iso offers.

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®

True to the Music

Twin-IsoTM

User Guide
Radial Engineering Ltd. 1845 Kingsway Ave., Port Coquitlam, BC V3C 1S9, Canada Tel: 604-942-1001 · Fax: 604-942-1010 email: [email protected]
Radial Twin-Iso user guide – Part #: R870 1025 00 / 10-2021 Appearances and specifications subject to change without notice. Copyright © 2017, all rights reserved.

WELCOME Congratulations on your purchase of the Radial Twin-Iso stereo (dual mono) line-level isolator. The Twin-Iso is a handy device that will allow you to isolate audio equipment and eliminate troublesome noise caused by ground loops.
The Radial Twin-Iso employs two high-performance Jensen isolation transformers to ensure the best signal transfer is enjoyed without artifacts or distortion. This makes the Twin-Iso a perfect choice where multiple consoles need to be sub-mixed, when isolating amplifier distribution racks and for connecting remote speaker towers. The Twin-Iso can also eliminate ground loop problems where equipment must be connected to alternate power sources such as generators.
As with all Radial products, the Twin-Iso is made with 14 gauge steel and features an internal welded I-beam frame for maximum rigidity. Switches and jacks are protected by our unique bookend construction, making the Twin-Iso virtually impossible to damage even in the most abusive touring environments.
We have purposely written this manual to be short, as most users will likely be familiar with the Twin-Iso’s applications. We do suggest that you take a moment to read through this document to familiarize yourself with the features that have been built in. For more detailed information, please visit the Radial website. This is where we post questions and answers that come from users after the product is released. If you do not find an answer, we invite you to send us an email at [email protected] and we will do our best to answer your query in a prompt and professional manner.
The Radial Twin-Iso is a wonderful device that will surely provide you with years of problem-solving connectivity. Enjoy!
INTRODUCTION The Radial Twin-Iso has been designed to provide electrical isolation between two line-level devices such as between two mixing consoles, remote speakers, crossovers and amplifier racks. Use the Twin-Iso anywhere source and destination devices may cause system noise because of different ground potentials (often referred to as ground loops).
So-called ground loops are caused by differing voltage references from various pieces of equipment that, when connected together, can introduce a 60 cycle hum in the sound system. Although there are various solutions that can be engineered to eliminate noise, the simplest and most effective is to isolate the source and destination with an audio transformer.
The Radial Twin-Iso employs two high-quality Jensen transformers to do the task. Jensen is renowned for their quality and the ability of their transformers to handle high signal levels without saturation and transfer the signal without introducing phase distortion or group delay. Although the cost is higher, a good quality transformer will assure the signal remains true to the source, resulting in better sound.
When you first pick up the Radial Twin-Iso, you will immediately notice the weight. This `hefty’ device employs a welded steel I-beam internal construction to assure the internal PCB will not torque, preventing part failure. Besides the heavy-duty enclosure, the extra-large transformers add to the Twin-Iso’s

Radial Engineering Ltd.

Twin-IsoTM User Guide

robustness. As a rule, the larger the transformer, the more signal handling capacity it will have and Jensen transformers can drive loads of 600 ohms up to +21dBu at 20Hz.
The Radial Twin-Iso is equipped with two XLR inputs and two XLR outputs. Each channel is 100% isolated from the other to eliminate cross-talk or interaction, thus allowing two completely different audio sources to use the Twin-Iso at the same time. Although the Twin-Iso is designed for +4dB professional line-level signals, the transformers will actually handle over 20dB without choking.
Each of the Twin-Iso’s outputs feature a 180° polarity reverse switch to ensure both consoles are `in phase’ and pushing the speakers in the same direction. This allows the Twin-Iso to feed a sub-group or auxiliary input of a console where polarity reversals are generally not provided. Finally, the Twin-Iso is equipped with a ground lift switch to further reduce system noise should it be present.
USING THE TWIN-ISO As with all Radial products, using the Twin-Iso is simple and straight forward. Make sure the sound system is turned off and all levels are set to zero before making audio connections. This will avoid any pops in the sound system that could cause damage to speakers.
The Twin-Iso is completely passive and does not require a power supply of any kind. Connect the source device to the Twin-Iso inputs. Connect the TwinIso outputs to the destination device. Turn the system up slowly and listen for noise. In the unlikely event you should encounter noise, simply depress the ground lift switch. That’s all there is to it.

AUX CONSOLE master outputs connect to Twin-Iso inputs.

MAIN CONSOLE Twin-Iso outputs feed main console.

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Twin-IsoTM User Guide

TWIN-ISO BLOCK DIAGRAM

LEFT IN

POLARITY

LEFT OUT

RIGHT IN

POLARITY

GND LIFT RIGHT OUT

J-RAK The optional J-RAKTM 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 finish.

J-CLAMP The optional J-CLAMPTM 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 finish.

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Twin-IsoTM User Guide

INPUT PANEL
1. Ground lift (inputs) Lifts the ground pin-1 on both XLR input connectors.
2. Input-1 & 2 For low impedance, balanced linelevel signals.
3. Bookend design 14 gauge steel outer shell creates protective zone around connectors and switches.
OUTPUT PANEL
4. Output-1 & 2 line-level transformer-isolated outputs.
5. Polarity reverse 180°Polarity reverse switch for outputs-1 & 2.
6. Full-bottom no-slip pad This provides electrical isolation and plenty of “stay-put” friction to keep the Twin-ISO in one place.
CONSTRUCTION
7. Ultra rigid steel I-beam enclosure eliminates stress that could torque the PC board and cause solder joint failure.
8. Jensen transformers offer outstanding audio performance.
9. Military-grade doublesided PCB with plated through-holes is bolted to welded steel standoffs.
10. Sturdy high-cycle PCB mounted switches are rated for long life.

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Twin-IsoTM User Guide

®

True to the Music

TWIN-ISO SPECIFICATIONS

Frequency response Max output level Phase distortion Total harmonic distortion Common-mode rejection Inputs Outputs Power requirement Size Weight

10Hz to 50kHz +/- 1dB +21dBu (20Hz, 1% THD) 0.3° at 20Hz 0.001% THD @1k, +4dBu (0.035% at 20Hz) 94dB @ 60Hz (83dB @ 3kHz) Balanced, line-level, pin-2 hot Balanced, line-level, pin-2 hot None, completely passive 3.25″ x 5″ x 1.875″ 2 lbs.

RADIAL LIMITED THREE YEAR TRANSFERABLE 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 finish 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 and transferable 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 modification 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.

Radial Engineering Ltd.

Twin-IsoTM User Guide