Omnia Volt User manual

On-air excitement and ultra-clean sound,
in a versatile and convenient package
MULTI-USE AUDIO PROCESSOR
INSTALLATION AND USERS GUIDE
Software Version 1.0, FM DSP|Core • April 2017
For Part Number: 2001-00439

UserWarnings and Contact Info
The installation and service instructions in this manual are for use by qualified personnel only.
To avoid electric shock, do not perform any servicing other than that contained in the operating
instructions unless you are qualified to do so. Refer all servicing to qualified personnel
This instrument has an autoranging line voltage input. Ensure the power voltage is within the
specified range of 100-240VAC. The ~ symbol, if used, indicates an alternating current supply.
This symbol, wherever it appears, alerts you to the presence of uninsulated, dangerous
voltage inside the enclosure – voltage which may be sufficient to constitute a risk of
shock.
This symbol, wherever it appears, alerts you to important operating and maintenance
instructions. Read the manual.
CAUTION: HAZARDOUS VOLTAGES
The instrument power supply incorporates an internal fuse. Hazardous voltages may still be
present on some of the primary parts even when the fuse has blown. If fuse replacement is
required, replace fuse only with same type and value for continued protection against fire.
WARNING:
The product’s power cord is the primary disconnect device. The socket outlet should be located
near the device and easily accessible. The unit should not be located such that access to the
power cord is impaired. If the unit is incorporated into an equipment rack, an easily accessible
safety disconnect device should be included in the rack design.
To reduce the risk of electrical shock, do not expose this product to rain or moisture. This unit is
for indoor use only.
This equipment requires the free flow of air for adequate cooling. Do not block the ventilation
openings on the rear and sides of the unit. Failure to allow proper ventilation could damage the
unit or create a fire hazard. Do not place the units on a carpet, bedding, or other materials that
could interfere with any panel ventilation openings.
If the equipment is used in a manner not specified by the manufacturer, the protection provided
by the equipment may be impaired.
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VOLT MANUAL

USA CLASS A COMPUTING DEVICE INFORMATION TO USER.
WARNING:
This equipment generates, uses, and can radiate radio-frequency energy. If it is not installed and
used as directed by this manual, it may cause interference to radio communication. This equip-
ment complies with the limits for a Class A computing device, as specified by FCC rules, part 15,
subpart j, which are designed to provide reasonable protection against such interference when
this type of equipment is operated in a commercial environment. Operation of this equipment
in a residential area is likely to cause interference. If it does, the user will be required to eliminate
the interference at the user’s expense. Note: objectionable interference to tv or radio reception
can occur if other devices are connected to this device without the use of shielded interconnect
cables. FCC rules require the use of shielded cables.
CANADA WARNING:
“This digital apparatus does not exceed the Class A limits for radio noise emissions set out in the
radio interference regulations of the Canadian department of communications.”
“Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques (de Class A) prescrites dans le règlement sur le brouillage
radioélectrique édicté par le ministère des communications du Canada.”
CE CONFORMANCE INFORMATION:
This device complies with the requirements of the EEC council directives:
♦93/68/EEC (CE MARKING)
♦73/23/EEC (SAFETY – LOW VOLTAGE DIRECTIVE)
♦89/336/EEC (ELECTROMAGNETIC COMPATIBILITY)
Conformity is declared to those standards: EN50081-1, EN50082-1.
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VOLT MANUAL

Trademarks and Licenses
Omnia and Omnia VOLT are trademarks of TLS Corp. All other trademarks are the property of
their respective holders.
All versions, claims of compatibility, trademarks, etc. of hardware and software products not
made by The Telos Alliance which are mentioned in this manual or accompanying material are
informational only. The Telos Alliance makes no endorsement of any particular product for any
purpose, nor claims any responsibility for operation or accuracy. We reserve the right to make
improvements or changes in the products described in this manual which may affect the product
specifications, or to revise the manual without notice.
This document and its content are copyrighted by TLS Corporation and may not be copied,
reproduced, or distributed in any form without expressed written permission.
Certain libraries are licensed to You under the terms of the GNU General Public License, Version
2 (“GNU GPL”). Telos is not allowed to sub-license these libraries to You as You are deemed to
have Your own direct license from the original licensee. Telos does not modify these libraries in
any way. Telos hereby offers to You, upon Your request and for the actual costs of materials and
shipping, all source code and object code files for all such GNU libraries contained in the Soft-
ware. Copyright (C) 1989, 1991 Free Software Foundation, Inc., 59 Temple Place, Suite 330,
Boston, MA 02111-1307 USA. Everyone is permitted to copy and distribute verbatim copies of
this license document, but changing it is not allowed.
Links to the GNU GPL and other modules used under license can be found in the About screen of
the VOLT Remote Control web interface.
Updates
Omnia VOLT’s features and operations are determined largely by software. The Telos Alliance
strives to provide the most stable and feature-rich software available. We encourage you to check
for software updates from time to time by visiting our website or by contacting us directly.
Feedback
We welcome feedback on any aspect of our products or this manual. In the past, many good
ideas from users have made their way into software revisions or new products. Please contact us
with your comments or suggestions.
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VOLT MANUAL

We support you…
By Phone/Fax
You may reach our Omnia Support Team in emergencies by calling [phone]. For
billing questions or other non-emergency technical questions, call [phone] between
9:00 AM to 5:00 PM USA Eastern Time, Monday through Friday.
By Email
Non-emergency technical support is available at [e-mail].
By Web
The Omnia Web site has a variety of information that may be useful for product selection and
support.
The URL is TelosAlliance.com/Omnia.
SERVICE
You must contact Telos Alliance before returning any equipment for factory service. We will
need your unit’s serial number, located on the back of the unit. We will issue a return authori-
zation number, which must be written on the exterior of your shipping container. Please do not
include cables or accessories unless specifically requested by the Technical Support Engineer.
Be sure to adequately insure your shipment for its replacement value. Packages without proper
authorization may be refused. US customers, please contact Telos Alliance Technical Support at
[phone]. All other customers should contact local representative to make arrange-
ments for service.
WARRANTY
Did you know that all Telos Alliance products come with a 5-Year Warranty?
This product is covered by a five year limited warranty, the full text of which appears at the end
of this manual.
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VI
VOLT MANUAL
REGISTER YOUR PRODUCT
Take a moment to activate your coverage online at: TelosAlliance.com/product-registration/
The Telos Alliance
1241 Superior Ave. Cleveland, OH 44114 USA
[phone]
For Omnia Support:
24/7 telephone [phone]
Email [email protected]
Web TelosAlliance.com/support-request

0User Warnings and Contact Info II
REGISTER YOUR PRODUCT . . . . . . . . . . . . . . . . . . . . V
A Letter from our CEO, Frank Foti . . . . . . . . . . . . . . . . .VII
1 Omnia VOLT Overview 1
2 VOLT in a hurry! 5
Step-by-step quick installation . . . . . . . . . . . . . . . . . 6
3 Installation and Rear Panel 8
Physical Installation . . . . . . . . . . . . . . . . . . . . . . 8
Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 Front Panel and LCD 14
Front Panel Meters . . . . . . . . . . . . . . . . . . . . . . .15
Using the Jog Wheel . . . . . . . . . . . . . . . . . . . . . .16
VOLT Front Panel Menu Map. . . . . . . . . . . . . . . . . . .19
5 Browser-based Remote Control 21
Logging In. . . . . . . . . . . . . . . . . . . . . . . . . . .21
Remote Screen. . . . . . . . . . . . . . . . . . . . . . . . .24
Remote Control Map . . . . . . . . . . . . . . . . . . . . . .27
6 VOLT Processing 28
Preset strategy and tuning . . . . . . . . . . . . . . . . . . .28
Processing Block Diagram . . . . . . . . . . . . . . . . . . . .32
VOLT Processing Terminology . . . . . . . . . . . . . . . . . .33
7 Troubleshooting and Updates 35
Contacting Us… . . . . . . . . . . . . . . . . . . . . . . . .35
8 Technical Specications 36
9 5-Year Warranty 38
Table of Contents
VII
VOLT MANUAL

War of the Waves
Dear Valued Customer,
It’s with great pride and a tip of the hat to an incredible team that I congratulate you on your new Telos
Alliance product. Everything we do here at the radio division of the Telos Alliance is with one end goal
in mind: To help broadcasters declare victory in extremely competitive environments. By purchasing
this product from us, in essence, you have declared war on your competition.
After all, the majority of Telos Alliance employees were broadcasters themselves once, and the products
we’ve developed over the years have been designed as solutions to specific issues faced on the front
lines of our industry. We’re right there in the trenches with you and have the weapons you need in your
arsenal.
Telos Systems is a catalyst to out-of-this-world sound, with the most powerful and popular broadcast
telephone systems in the industry; IP/ISDN codecs and transceivers; plus processing/encoding for
streaming audio. We built an industry on the back of these amazing telephony systems, and they are still
going strong.
While we at the Telos Alliance never forget our roots, we are also blazing trails in terms of new technolo-
gies like stream-encoding and AoIP, so that all types of broadcasters can excel in this ever-evolving digital
world.
Omnia Audio not only lets you stand out on the dial with your unique signature sound via legendary
audio processors, audio codecs, and microphone processing, it lets you give your listeners a better
streaming experience across devices with innovative stream encoding/processing software and hard-
ware.
Axia Audio is a driving force behind the AES67 AoIP standard, and its networked AoIP radio consoles,
audio interfaces, networked intercom, and software products continue to move AoIP adoption forward
and help broadcasters streamline operations with cohesive, smart, and feature-rich AoIP ecosystems.
Last, but certainly not least, 25-Seven has traditionally been known for its audio delays, but its Voltair
watermark monitor/processor has made a name for itself more recently as the disruptive product that
helped broadcasters take back their ratings and harness the true power of their listening audiences.
You work so hard on your programming day-in and day-out, it deserves technology that will optimize
sound and performance at every point in the airchain and online. Armed with Telos products, you have
what you need to set your competition squarely in your crosshairs.
With that, I’ll leave you to prep your armaments. I hope that you will enjoy your Telos Alliance products
for many years to come!
Sincerely,
Frank Foti
CEO, The Telos Alliance

1 Omnia VOLT Overview
Nobody knows processing like Omnia…
For more than thirty years, we’ve been at the front of broadcast audio processing. In that time
Omnia has earned a reputation for market-leading loudness and a clean, undistorted on-air
sound.
…and nobody knows broadcast DSP like Telos
We’ve also been Digital Signal Processing pioneers, introducing the first DSP-based Telephone
Talk Show system, the Zephyr ISDN codec, and the first all-digital FM airchain processor.
And we’ve continued to lead, with Axia—the first AoIP audio and control networking system de-
signed specifically for broadcasters, with our ground-breaking Voltair watermark enhancement
systems, with our Linear Acoustic loudness and surround management products, and more.
Though it all, we’ve maintained one goal for Omnia: to apply cutting-edge technology, that can
give your station a competitive, exciting, market-leading sound that gets and holds listeners.
Now, with Omnia VOLT, we’ve gone even further!
We’ve rewritten the rules for broadcast DSP, fine-tuning our algorithms to bring you:
♦Unprecedented processing power and sound in a one-rack-unit package,
♦Easy setup without sacrificing your ability to customize exactly the sound you want, and
♦Future-proof versatility.
Omnia VOLT is… a signal that jumps out of listeners’ radios. With the pristine, warm
Omnia sound broadcasters love.
♦A new generation Frank Foti-designed Clipper for stronger on-air sound without grunge.
♦Six Separate AGC Sections: One wideband, plus five separate time-aligned narrow band
sections, each with separate controls for every important parameter. Plus a tunable mid-
band crossover. Give your station the loudness and consistent sound you want!
♦Five Separate Time-Aligned Limiter Sections, each with separate Drive, Hold, Threshold,
and Attack/ Decay controls. They give you protection against overmodulation while
maintaining a loud signature sound.
1

♦Variable Deep Bass, Phat Bass, and Warmth enhancers. Get that meaty Omnia sound,
fine-tuned the way you want.
♦Bass Pre-Clipper. Fully adjustable with Tightness and Girth controls. You’ll have strong,
listener-pleasing bass without worrying about intermodulation distortion.
♦Clipper Silk adjustment. If your format is prone to treble distortion, you can add just
enough Silk to clean up those high frequencies.
♦Sensus processing for digital program streams. Omnia’s exclusive Sensus algorithms
actually predict how HD, DRM, or multicasting data reduction will affect your sound. They
pre-condition your signal, making compression sound better—even at low bitrates.
♦Adjustable BS-412 Threshold and Processing for full compliance with ITU standards.
♦Stereo Enhancement for FM Analog, without adding multipath. You’ll get a wider, more
exciting signal that jumps out of the radio.
♦Variable high-pass and switchable phase rotator. Those ultra- low frequencies, too low to
be perceived as bass by listeners, won’t rob you of on-air power.
♦Automatic mono “dry voice” sensing. Ideal for FM Analog Stereo stations using extreme
processing: it keeps an extra hand on the clipper, to stop distortion when the L+R channel
gets boosted by mono signals.
Omnia VOLT is… fast setup and ease-of-use, while giving you absolute control of
every important parameter.
We’ve built VOLT for users who need to get results fast, and for those who like to customize
their station’s sound. You can get VOLT on the air in minutes, select presets that have been
designed for today’s stations and programming, create a unique sonic personality with just a few
nudges of the QuickTweak™ sliders, fine-tune it with a comprehensive Graphic User Interface,
save settings for your automation to trigger at different dayparts, and share those presets with
other VOLT users in your group.
♦Choose from some of the best factory presets on the air. They’re designed by Omnia’s
processing experts, and by our favorite “insider” guest programmers.
♦Then use Omnia VOLT’s exclusive QuickTweak system, to fine-tune your sound fast.
Get exactly the processing you want, while you’re on the air, right from the front panel or a
connected computer.
¸Nobody knows processing like Omnia. We’ve designed QuickTweak based on our
decades of experience. It links complex and interactive parameters—some of which can’t
be reached by normal processor controls—to create a core set of “meta” controls.
CHAPTER 1 | 2
OMNIA VOLT OVERVIEW

¸QuickTweak is easy to understand: controls are intuitive, you can tune them by ear, and
you hear the results instantly.
¸You can use QuickTweak on the factory presets, or on your own custom processing.
¸You can save your own preset file after using QuickTweak, and recall it instantly.
¸You can continue to QuickTweak or fine-tune your settings, even you’ve saved a file, if
your needs change or you want to refine the sound.
¸Customize a unique sound for your station and market. Omnia VOLT’s Graphic User
Interface is easy to navigate, but gives you the deep level of control you need.
Omnia VOLT is future-proof versatility, at no extra charge!
COR E
DSP
♦VOLT’s DSP|Core firmware modules let you rearrange and modify VOLT’s internal
architecture, as your needs change:
♦Use VOLT for FM Analog Stereo at the station, with high-quality baseband clipping to feed
uncompressed STLs, or at the transmitter, with dual composite outputs.
♦Use VOLT for AM Broadcast, with purpose-built presets for the challenges of AM radio.
VOLT’s Tunable Asymmetrical Modulation and Tilt help you get modern results, even
from older transmitters!
♦Use VOLT for Studio and Multicast for HD/DRM/Web and other compressed media, plus
program and syndication production. Our exclusive Sensus algorithms reduce compres-
sion artifacts even at low bitrates.
♦Use VOLT Stereo Generator when you need to split your system between a main processor at
the station, and a dedicated MPX stereo generator at the transmitter site.
♦Use VOLT with Low-latency FM to comply with local regulations, using a high efficiency
clipper that’s optimized for less than 7 ms latency.
DSP|Cores aren’t extra cost add-ons!
♦Download the DSP|Core firmware package you need for free, from Telos’ website…
♦Transfer it to your VOLT from any network computer, and…
♦Reboot. It’s that simple!
CHAPTER 1 | 3
OMNIA VOLT OVERVIEW

You can switch applications whenever your needs change. Or keep a spare Omnia VOLT as
backup for every one of your standby processors, in all your stations!
DSP|Core is almost something for nothing! There are just two small caveats:
1. Some Omnia VOLT features aren’t applicable to every processing need. (Obviously, you
don’t need dual composite outputs on a processor you’re using for webcasting.) Each
DSP|Core firmware package has a feature set that’s fine-tuned for its application, and
allocates DSP where it’s needed most.
2. Some DSP|Core firmware modules are still being tested and refined while we introduce
others. Check our website for updates.
Omnia VOLT installs quickly, with setup and convenience features for today’s broad-
caster:
♦VOLT includes a built-in HTML-5 server for full control from any computer, tablet, or
smartphone… it doesn’t need Java or special plug-ins, so there’s no worry about those
vulnerabilities.
♦Totally flexible signal path. You can choose analog, AES/EBU digital, or Livewire inputs;
choose which channel to use for mono inputs; use analog, AES/EBU digital, Livewire, or
composite outputs… or all the outputs at the same time. There are separate volume and
channel balance trims, and flexible “flip-phase options”, on each input. You can save and
recall custom input/output setups for different applications.
♦Switchable insert points for Voltair, watermark encoders, or other downstream encoding.
You can feed encoders with a pre-processed signal from VOLT’s multiband AGC and
limiters. That way, your encoder sees a stronger, more reliable signal. Then feed the
encoder’s output back into VOLT, for post-encoding clipping that protects you against
overmodulation.
♦Automatic “failover” signal switching. You can specify a backup input for use if your main
signal drops outs. VOLT can switch to this source automatically, with adjustable sensitivi-
ty, or you can trigger the changeover via contact closure or Livewire GPIO as needed.
♦Rugged one-rack-unit construction fits any control room, technical center, or transmitter
shack, with easy-to-see LED meters.
♦Fanless operation. Feel free to use VOLT near critical monitoring or live mics.
♦Flexible Pre-Emphasis Switching on both input and output. This makes it easy to fit VOLT
into any existing airchain.
♦Built-in tone generator. It lets you verify meter readings and signal path quickly.
♦In addition, the FM Stereo Generator DSP|Core provides:
♦Dual Variable Composite Outputs to feed a main and backup transmitter.
♦Variable Pilot Level and Phase let you adjust the signal for transmission.
♦Adjustable SCA input for additional services, with 19 kHz sync output to synchronize
external generators.
CHAPTER 1 | 4
OMNIA VOLT OVERVIEW

2 VOLT in a hurry!
We understand there are times you need to get equipment up and running quickly, and don’t
have time to learn all it can do1. This chapter is for those times.
VOLT is a fully tunable and sophisticated processor that can be set up for AM or FM, analog or
digital broadcasting, Web and other compressed media, or studio and program production.
♦With VOLT, you can achieve a market-leading sound using just our factory presets.
♦Then you can customize the sound easily, right from the front panel,
with our exclusive QuickTweak system: six intuitively labeled sliders,
designed by processing experts, each controlling specific aspects of your
sound—some of which can’t be adjusted by normal processor controls.
You can fine-tune them in real-time, hear the results as you do, and save
the ones you like as your own personal presets.
♦But VOLT also lets you go deep. More than 140 easily accessible and interactive processing
and routing adjustments let you get just the sound you want. They let you choose, balance,
and condition input signals from analog, AES/EBU digital, or Livewire sources. They allow
automatic “failover” signal switching if your main program source fails. They let you insert
watermark ID encoders and our Voltair watermark processor after your signal has been
processed for strength and reliability, but before the protection and loudness of VOLT’s
ultra-clean clipper.
♦
COR E
DSP
VOLT can even become totally different processors whenever your needs
change! Our five free, downloadable DSP|Core firmware packages re-allo-
cate VOLT’s internal resources for your purpose. You can have an FM
analog processor with complete Omnia control and internal composite
stereo generator today… turn it into a fully featured digital streaming processor with
exclusive artifact-reducing Sensus processing tomorrow… change it to an ultimate AM
processor with sophisticated bass and asymmetry enhancement a day later… or use it for
ultimate control of studio or syndicated programming after that! Any VOLT DSP|Core
package can be loaded at any time, as your needs change.
1 In some stations, this may be the normal mode. So we build sophisticated devices that can be used quickly
and intuitively. But VOLT is also powerful and versatile: if you use this manual, you’ll learn all the other useful
things your new Omnia can do.
5

Omnia VOLT is a lot of processor. We couldn’t put all of it into an introductory, quick-start
chapter. To learn all it can do for you, you’ll have to read the rest of this book. (If you don’t have
enough time to do that, at least scan the table of contents, and see which chapters will be most
useful.)
Step-by-step
These dozen (or fewer, depending on setup) steps assume you’re running VOLT from its front
panel. There’s also an extensive Remote Control, described later in this manual.
1. Install VOLT in your rack, connecting audio input and outputs appropriate for your sys-
tem.
2. If using the composite generator, connect one of the composite outputs to your exciter.
3. Connect AC power. There is no power switch. Wait for the system to stabilize and the LCD
to say Omnia VOLT.
4. Navigate to Input/Output >Input and select the appropriate Input Src.
5. Feed regular program material at your station’s normal level (usually 0 VU on the console
meters). Adjust VOLT’s appropriate Level so its input LEDs bounce up to -16 or -12. Exit
back to Main Menu.
6. If you’re using an audio-input monitor, transmitter, or STL, navigate to Input/Output
>Output and adjust the appropriate Level for the next device. Exit back to Input/
Output.
7. Navigate to Output >FM Options, and select the FM Pre-emph (pre-emphasis) setting
required for your country or region.
♦If BS-412 power limiting is required, turn it on in this menu.
♦If you’ve chosen an audio-frequency input device in step 6, select the appropriate De-emph
for that device’s signal.
♦If you’re feeding an uncompressed digital STL, or want to use an audio output to feed the
exciter, turn De-emph off for that output. This means VOLT’s FM Pre-emph, selected at
the start of this step, stays as part of the signal to the STL.
VOLT should be the only device providing pre-emphasis or limiting. This means you should
disable any additional pre-emphasis or limiting in the exciter.
8. If you’re using a composite output, navigate to Input/Output >Stereo Generator, then
adjust Comp 1or Comp 2for 100% modulation, and Pilot Lvl for between 8% - 10%. Exit
back to Main Menu.
9. Navigate to Processing >Preset, feed normal program material, and choose a preset for
your initial setup. You’ll be able to change the preset and/or fine-tune its settings later.
CHAPTER 2 | 6
VOLT IN A HURRY!

10. Navigate to QuickTweak >Clip Drive and set the drive for the best compromise between
loudness and distortion. You’ll be able to refine this adjustment in many ways, later. Exit
back to Main Menu.
11. Navigate to Save Preset, and provide a name for the settings you just created. This can
serve as a baseline while you do step #12:
12. Read the rest of this manual. Learn how to shape your sound with the best Omnia process-
ing for your station and market. Take the time to experiment, and enjoy the results!
CHAPTER 2 | 7
VOLT IN A HURRY!

3 Installation and Rear Panel
Physical Installation
Studio or Transmitter?
Obviously, if you’re using VOLT’s internal stereo generator with composite output, it should be
close to the transmitter(s)2. All operating functions can be controlled easily over a network, so
you’ve got complete flexibility to tune a transmitter’s VOLT from the studio.
But if you’re planning to locate VOLT at the station and feed Left / Right audio (with no sub-
carrier) to a transmitter via STL, make sure the STL is linear, and does not use data reduction
or compression. This may be non-intuitive: after all, today’s best compressed STLs can sound
pretty good. The problem is that lossy compression algorithms are designed for normal, unpro-
cessed speech and music in normal listening situations. VOLT optimizes your signal for trans-
mission, and the clipper is designed to create maximum loudness with minimum distortion
when broadcast. This can create waveforms that sound great on the air… but break the lossy
compression schemes in some STLs. The result that the STL will create extra distortion and lack
of clarity, before the signal even gets to the transmitter.
This warning also applies to HD and DRM transmission using VOLT’s Multicast DSP|Core. Our
exclusive Sensus processing can actually eliminate some of the distortions of those compressed
media. But “double compression”—first, through a lossy STL, and then through a compressed
digital media transmitter—can create unpredictable interactions that even Sensus can’t fix.
Increasingly, facilities with high bandwidth ber links between their studios and transmitter sites
are discovering that Livewire AoIP can be used for high reliability, lossless STL. It lets you feed
a VOLT at the transmitter using Livewire Xnode at the studio, or use VOLT at the studio to send
processed AoIP audio to the transmitter. The Livewire capability built into every VOLT lets you take
advantage of today’s faster and cheaper IP bandwidth, with ever-increasing STL options.
2 VOLT has two separately adjustable composite outputs, so you can drive a main transmitter and backup
simultaneously.
8

Rack mounting
VOLT is only one rack unit high, and can mount almost anywhere.
Like most sophisticated equipment, it can be damaged by extreme heat.
♦Do not mount it directly above or below equipment that normally runs warm. For best
air circulation, make sure whatever is mounted below it is very shallow: a blank panel, or
something like a patchbay that doesn’t generate heat.
♦Do not block the ventilation grills on VOLT’s sides. There should be at least an inch of air
space on both sides of the unit. Most racks provide this.
♦Do not block the ventilation holes on VOLT’s back.
There’s a lot of electronics in VOLT’s chassis, so it has to be fairly deep: about 11½” plus con-
nectors. While it’s not particularly heavy, that depth has to be cantilevered by the one-unit front
panel: To prevent damage to the front panel, always mount with four rack screws. If you must
use only two screws temporarily, use both bottom screw holes. That distributes the weight better.
Live studio?
VOLT does not have an internal fan, and can be located near a live mic. This makes our Multicast
DSP|Core version ideal for high quality podcasting and other small operations.
Hookup
Audio connections
We designed VOLT’s audio routing to be extremely flexible:
♦You can connect VOLT via balanced analog, AES/EBU digital, or Livewire AoIP. Each
input can have a different program stream, and you can select which input gets broadcast
on the front-panel LCD or from a connected computer. You can also designate one input
for automatic or manual “failover” backup of the same programming, if the main link is
disrupted.
♦Each input and output can be adjusted independently: you can set any level between -12
and +12 dB of nominal, or trim the channel balance ±3 dB, in precise .1 dB steps.
♦Each input can also be adjusted independently for polarity3 with normal or inversion on
either or both input channels. Input signals can be independently set for normal L/R or
flipped R/L stereo, or mono from either channel or both summed.
3 Sometimes referred to as“phase”.
CHAPTER 3 | 9
INSTALLATION AND REAR PANEL

Insert Point
Normally, all of VOLT’s audio outputs will carry the fully processed output. You can use them to
distribute analog to nearby monitors, for example, while sending digital audio to a control room
via AES/EBU or Livewire.
However, you can also break VOLT’s internal signal path for use with a third party watermark
identification or EAS generator, or for our 25-Seven Voltair watermark enhancement and man-
agement system.
♦The external device will be fed from VOLT’s multiband Limiter, after all enhancement and
AGC. This way, watermark encoders can take advantage of Omnia presets that boost the
critical frequencies for electronic ratings systems.
♦The external generator or Voltair output is applied directly to VOLT’s drive control of the
final clipper or limiter4. This way, you don’t have to worry about an encoder’s added signal
driving your transmitter into overmodulation.
VOLT’s insert output becomes the “send” for your external device, and can be any one of
VOLT’s three audio outputs. The insert input (“return” from the external device) can be any
input you’re not using for program stream or failover backup. Insert input and output don’t have
to be the same mode—one can be analog, for example, while the other is AES/EBU—though this
rarely occurs in practice.
Insert points are designated using VOLT’s network Remote Control. See that chapter for details.
Analog connections
These are balanced input and output, +4 dBu nominal. At nominal level, there is +18 dB head-
room available.
Inputs can be fed from any transformer or electronically balanced sources. The input impedance
is 10kΩ. Outputs are electronically balanced, for any load of 600Ωor higher.
We do not recommend using VOLT in an unbalanced environment. If you must hook it up to
unbalanced equipment, use a buffer amp or transformer.
Connectors are standard XLR-3 male and female: pin 1 ground, pin 2 “hot”, pin 3 return.
AES/EBU connections
Input is stereo, transformer isolated and balanced 110Ωnominal per AES/EBU standard, with 24
bit resolution. Input automatically locks to any sample rate between 32 kHz and 108 kHz.
Output is stereo per AES3 professional standard, transformer isolated and balanced 110Ω
nominal. Output sample rate can be locked to the input, locked to an external sync source, or
use VOLT’s internal 48 kHz clock. AES/EBU output level is -18 dBFS nominal; like all VOLT’s
outputs, it can be adjusted over a 24 dB range.
4 Depending on which DSP|Core version is loaded.
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Connectors are RJ-45 female, EMI-suppressed and wired according to StudioHub+®standard.
AES/EBU program input and output appear on pins 1+2 of the corresponding RJ-45, with pin 4
as ground. StudioHub+ adapters are included with VOLT5: use the XLR connectors with a green
color sleeve.
If you want to apply an external sync signal for AES/EBU, use pins 3+6 of the input RJ-45; this
is the XLR female with a red color sleeve on our adapter. Sync source should be an AES/EBU
stream (often called “digital black”); VOLT does not sync to an unbalanced 75Ωword clock.
Livewire
Connect a Livewire Audio-over-IP network to the Livewire/LAN RJ-45 jack. Livewire must be
configured from a connected computer; see the chapter on Remote Control.
Don’t Know Jack?
StudioHub+ inputs and outputs, and Livewire or Ethernet LAN, all use identical RJ-45 connectors. You
can’t tell which is which by feel. Before connecting, look at the back-panel silk screening or the photo
in this chapter to make sure you’ve got the right one.
Composite connections
These are usable only if your VOLT is running an FM or FM Stereo Generator DSP|Core.
Composite Outputs
These are identical 75Ωoutputs to feed a multiplex signal to your transmitter(s). Each is sepa-
rately adjustable from 0 V to 10 V pp in .5v steps. Pre-emphasis curve and mode, pilot level and
phase, and stereo separation are also adjustable. See the chapter on Remote Control for details.
SCA Input and Gain
This 75Ωinput can be used for Subsidiary Communications (SCA) such as reading for the blind
or data casting. A signal from an external SCA or RDS generator, at this input, is mixed into both
composite outputs.
The Gain trimmer lets you adjust between -29 dB and +2.6 dB, accommodating signals between
10V and .25 V p-p for 8.6% injection on a 3.6 V composite output.
19k Sync Out
This is a TTL-level 19 kHz square wave, locked to VOLT’s stereo pilot, for use as a reference for
most RDS or SCA generators that operate at multiples of the 19 kHz pilot frequency.
5 Get additional adapters from your local dealer or http://www.radiosystems.com. Some stations prefer to run
AES/EBU over Cat-5 or Cat-6 cables with RJ-45; full connection details are at http://www.studiohub.com.
CHAPTER 3 | 11
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Data Connectors
Serial I/O
This is a DB9-M for factory maintenance; it is not used in normal VOLT operation.
GPI
This is a DB9-F for remote control input, using contact closures or other logic-level systems.
Pin 1 +5VDC Out
Pin 2 Input Common +
Pin 3-6 Trigger input #1 - #4
Pin 7,8,9 GND
The action for each input is controlled by the GPIO/Events tab in the Remote Control.
If using pushbuttons or relays, each GPI activates by momentarily connecting its Trigger input
to Ground, while pin 1 is tied to pin 2. (For noise immunity, you may wish to pull the input line
“normal high” by connecting it to the +5V supply through a 1kΩresistor.)
If triggering from a logic source, the source’s continuous positive voltage should go to pin 2, and
each output should pull its corresponding input pin low when active. Systems using TTL levels
can be connected directly. Systems working at higher voltages will require a dropping resistor in
series with each input:
Input Voltage Required Resistor
5 VDC none
6 VDC none
12 VDC 680Ω, ¼ Watt
24 VDC 1.8kΩ, ½ Watt
48 VDC 3.9kΩ, 1 Watt
The source must be capable of providing up to 40 mA.
General Purpose Outputs are available only at the Livewire connector.
LIVEWIRE / LAN
This is an RJ-45 for 10Base-T and 100Base-T Ethernet connection. It can be used for Livewire
audio, remote control with a connected computer, or both. See Livewire and Remote Control
chapters for details.
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