Antares ATR-1a User Manual

©2000 Antares Audio Technologies. All Rights Reserved.
Antares Audio Technologies

231 Technology Circle, Scotts Valley, California 95066 USA
voice: [phone]

fax: [phone]
service: [phone]
web: www.antarestech.com

Printed in USA Rev 1.0-10/00

Contents

Getting Started

Welcome 5
Tech Support 6
A few words from Dr. Andy 7

Introducing the ATR-1a Chapter 1

Background 9
So what exactly is it? 9
A little bit about pitch 10
Some pitch terminology 10
How the ATR-1a determines pitch 11
How the ATR-1a corrects pitch 12
Program Mode vs. Song Mode 13

Setting Up the ATR-1a Chapter 2

Setting up the ATR-1a 15

Panel Controls and Chapter 3
Connectors

Front panel 17
Back panel 19

Display Screens and Chapter 4
Menu Pages

Flash screen 20
Mode pages 20
Program Edit pages 22

Speed page 23
Make Scale from MIDI page 24
Scale page 24
Vibrato page 26

Program Name page 27
Save Program page 27

Song Edit pages 27

Song Speed page 28
Song Items page 28
Song Vibrato page 29
Song Name page 30
Save Song page 30

System Edit pages 30

Bass Mode page 31
Sensitivity and LCD page 31
Foot Switch and Detune page 32
MIDI page 1 33
MIDI page 2 34
MIDI page 3 35
MIDI page 4 35
MIDI page 5 36
Owner Message page 36

Creative Applications Chapter 5 37

Appendix

Factory Programs 40
Scale and Chord Guides 41
MIDI SysEx message formats 44
MIDI SysEx message examples 47
MIDI Implementation Chart 50
ATR-1a Specifications 51

Index 52

Welcome!

On behalf of everyone at Antares Audio Technologies, we’d like to offer
both our thanks and congratulations on your decision to purchase the
absolute best intonation correction hardware in the world.

Before you proceed much farther, we’d like to strongly encourage you to
fill out and return the ATR-1a registration card. As an ATR-1a owner, you
are entitled to receive notification of any firmware upgrades, technical
support, and advance announcements of upcoming products. But we
can’t send you stuff unless we know who and where you are. So please,
send it in.

At Antares, we are committed to excellence in quality, customer service,
and technological innovation. With your purchase of the ATR-1a, you
have created a relationship with Antares which we hope will be long
and gratifying. Let us know what you think. You can count on us to
listen to you.

Again, thanks.
The Whole Antares Crew

5

Technical Support

In the unlikely event that you experience a problem using your ATR-1a,
try the following:

1. Make another quick scan through this manual. Who knows? You may
have stumbled onto some feature that you didn’t notice the first time
through.

2. Check our web page for tips, techniques, or any late-breaking
information: www.antarestech.com

3. Call your local Antares dealer.

4. Call us at [phone] Monday through Friday between 9am and
5pm USA Pacific Standard Time.

5. Email us at: [e-mail]

For options 3, 4 and 5, please be prepared to provide the serial number of
your ATR-1a.

6

A few words fr om Dr. Andy

I remember, as if it were yesterday, sitting in my junior high school band,
happily playing away on my flute, when I noticed that our conductor was
screaming and jumping up and down on the podium. What was this
about? Suddenly, I realized she was screaming at me. And just in time too
— since I was able to duck and watch a baton fly past my head, missing
me by inches. “Why [expletive] can’t you play in tune?” she asked. But I
was in tune. Everybody else was out of tune. It was then I began to learn
about intonation.

Many artists struggle with intonation. An entire concert can be spoiled by
a single sour note. Many of our most celebrated entertainers spend hours
in the studio doing retake after retake, trying to sing expressively and in
tune. Afterwards, their producers spend yet more time trying to correct
intonation problems using inadequate tools.

The ATR-1a is dramatically changing all of that. Because of the ATR-1a,
sessions can focus on feeling and expression, rather than retakes. Studio
hours are reduced and production costs are lowered. Even artists in live
performance situations can concentrate on interpretation, confident that
any pitch inaccuracies will be caught and corrected before they make it
out to the audience.

What’s more, the ATR-1a is incredibly easy to use (a fact attested to by the
thinness of this manual). So fire up your ATR-1a, invest a half hour or so in
reading the following pages, and prepare to make intonation problems a
thing of the past.

Andy Hildebrand Ph.D.
Founder and Chief Scientist
[e-mail]

7

8

Chapter 1:
Introducing the ATR-1a

Some background

In 1997, Antares first introduced the ground-breaking Auto-Tune Pitch
Correcting Plug-In for ProTools™ (followed a bit later by the VST and
stand-alone versions). Here was a tool that actually corrected the pitch
of vocals and other solo instruments, in real time, without distortion or
artifacts, while preserving all of the expressive nuance of the original
performance. Recording Magazine called Auto-Tune a “Holy Grail of
recording.” And went on to say, “Bottom line, Auto-Tune is amazing...
Everyone with a Mac should have this program.” In fact, we know of
quite a few people who bought kilo-buck ProTools systems just to be
able to run Auto-Tune.

While Auto-Tune has met with tremendous success, we were immediately
barraged with requests for a self-contained “Auto-Tune-in-a-box.” The
result is the ATR-1a which you have presumably just purchased.

So what exactly is it?

The ATR-1a is a rack-mountable hardware implementation of Antares’s
Auto-Tune pitch correcting software. Like Auto-Tune, the ATR-1a employs
state-of-the-art digital signal processing algorithms (many, interestingly
enough, drawn from the geophysical industry) to continuously detect the
pitch of a periodic input signal (typically a solo voice or instrument) and
instantly and seamlessly change it to a desired pitch (defined by any of a
number of user-programmable scales).

In addition, the ATR-1a, befitting its easy portability, includes a number
of new features that make it particularly powerful in live performance
situations. These include a new Song Mode that lets the ATR-1a follow
even the most complex harmonic song structures, foot switch control of
Scale selection and Bypass Mode, as well as MIDI control of every ATR-1a
parameter.

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A little bit about pitch

Pitch is typically associated with our perception of the “highness” or
“lowness” of a particular sound. Our perception of pitch ranges from the

very general (the high pitch of hissing steam, the low pitch of the rumble
of an earthquake) to the very specific (the exact pitch of a solo singer or
violinist). There is, of course, a wide range of variation in the middle. A
symphony orchestra playing a scale in unison, for example, results in an
extremely complex waveform, yet you are still able to easily sense the
pitch.

The vocalists and the solo instruments that the ATR-1a is designed to
process have a very clearly defined quality of pitch. The sound-generating
mechanism of these sources is a vibrating element (vocal chords, a string,
an air column, etc.). The sound that is thus generated can be graphically
represented as a waveform (a graph of the sound’s pressure over time)
that is periodic. This means that each cycle of waveform repeats itself
fairly exactly, as in the periodic waveform shown in the diagram below:

Because of its periodic nature, this sound’s pitch can be easily identified
and processed by the ATR-1a.

Other sounds are more complex. This waveform:

is of a violin section playing a single tone. Our ears still sense a specific
pitch, but the waveform does not repeat itself. This waveform is a summa­tion of a number of individually periodic violins. The summation is non­periodic because the individual violins are slightly out of tune with respect
to one another. Because of this lack of periodicity, the ATR-1a would not
be able to process this sound.

Some pitch terminology

The pitch of a periodic waveform is defined as the number of times the
periodic element repeats in one second. This is measured in Hertz (abbre­viated Hz.). For example, the pitch of A3 (the A above middle C on a
piano) is traditionally 440Hz (although that standard varies by a few Hz.
in various parts of the world).

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Pitches are often described relative to one another as intervals, or ratios of
frequency. For example, two pitches are said to be one octave apart if
their frequencies differ by a factor of two. Pitch ratios are measured in
units called cents. There are 1200 cents per octave. For example, two tones
that are 2400 cents apart are two octaves apart.

The traditional twelve-tone Equal Tempered Scale that is used (or rather
approximated) in 99.9% of all Western tonal music consists of tones that
are, by definition, 100 cents apart. This interval of 100 cents is called a
semitone.

How the ATR-1a detects pitch

In order for the ATR-1a to automatically correct pitch, it must first detect
the pitch of the input sound. Calculating the pitch of a periodic waveform
is a straighforward process. Simply measure the time between repetitions
of the waveform. Divide this time into one, and you have the frequency in
Hertz. The ATR-1a does exactly this: It looks for a periodically repeating
waveform and calculates the time interval between repetitions.

The pitch detection algorithm in the ATR-1a is virtually instantaneous. It
can recognize the repetition in a periodic sound within a few cycles. This
usually occurs before the sound has sufficient amplitude to be heard. Used
in combination with a slight processing delay (no greater than 4 millisec­onds), the output pitch can be detected and corrected without artifacts in
a seamless and continuous fashion.

The ATR-1a was designed to detect and correct pitches up to the pitch C6.
If the input pitch is higher than C6, the ATR-1a will often interpret the
pitch an octave lower. This is because it interprets a two cycle repetition as
a one cycle repetition. On the low end, the ATR-1a will detect pitches as
low as A0 (55Hz) in its normal mode and down to 25Hz when Bass Mode is
selected. This range of pitches allows intonation correction to be per­formed on all vocals and almost all instruments.

Of course, the ATR-1a will not detect pitch when the input waveform is
not periodic. As demonstrated above, the ATR-1a will fail to tune up even
a unison violin section. But this can also occasionally be a problem with
solo voice and solo instruments as well. Consider, for example, an excep­tionally breathy voice, or a voice recorded in an unavoidably noisy envi­ronment. The added signal is non-periodic, and the ATR-1a will have
difficulty determining the pitch of the composite (voice + noise) sound.
Luckily, there is a control (the SENSITIVITY control, discussed in Chapter 4)
that will let the ATR-1a be a bit more casual about what it considers
“periodic.” Experimenting with this setting will often allow the ATR-1a to
track even noisy signals.

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How the ATR-1a corrects pitch

The ATR-1a works by continuously tracking the pitch of an input sound
and comparing it to a user-defined scale. The scale tone closest to the
input is continuously identified. If the input pitch exactly matches the scale
tone, no correction is applied. If the input pitch varies from the desired
scale pitch, an output pitch is generated which is closer to the scale tone
than the input pitch. (The exact amount of correction is controlled by the
Speed parameter, described below and in Chapter 4.)

Scales

The heart of the ATR-1a’s pitch correction is the Scale. The ATR-1a allows
you to program 50 different Scales. For each Scale you can define which
notes will sound and which won’t. And for each note that will sound, you
can decide whether the ATR-1a will apply pitch correction to input pitches
near that note or leave those pitches uncorrected.

Speed

You also have control over how rapidly, in time, the pitch adjustment is
made toward the scale tone. This is set with the SPEED control (see
Chapter 4 for more details).

• Fast SPEED settings are more appropriate for short duration notes and
for mechanical instruments, like an oboe or clarinet, whose pitch
typically changes almost instantly. A fast enough setting will also
minimize or completely remove a vibrato.

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• Slow SPEED settings, on the other hand, are appropriate for longer
notes where you want expressive pitch gestures (like vibrato) to come
through at the output and for vocal and instrumental styles that are
typified by gradual slides (portamento) between pitches. An appropri­ately selected slow setting can leave a vibrato unmodified while the
average pitch is accurately adjusted to be in-tune.

Vibrato

The ATR-1a can also apply a vibrato to the input sound. You can program
the vibrato depth, vibrato rate and the onset delay of the vibrato (or even
control it in real time via MIDI). You can also choose the shape of the pitch
variation in the vibrato (sine, ramp or square). By combining a fast Speed
setting with the ATR-1a Vibrato settings, you can even remove a
performer’s own vibrato and replace it with the ATR-1a’s programmed
vibrato, all in real time. Also, unusual combinations of Vibrato Waveform,
Rate and Depth settings can be used for some interesting special effects.

An example

As an example, consider this before-and-after graphic representation of
the pitch of a vocal phrase that contains both vibrato and expressive
gestures.

CORRECTED
BY ATR-1

ORIGINAL
PERFORMANCE

In the original performance, we can see that although the final note
should be centered around D, the vocalist allowed the tail of the note to
fall nearly three semitones flat. The “after” plot is the result of passing
this phrase through the ATR-1a with a Program consisting of a D Major
Scale (with C
causes the pitch center to be moved to D, while still retaining the vibrato
and expressive gestures. (Setting C
the ATR-1a from trying to correct the seriously flat tail of the last note to
those pitches. See Chapter 4 for more details.)



and B set to ”Blank”) and a Speed setting of 10. That Speed



and B to ”Blank” is necessary to keep

Program Mode vs. Song Mode

At its top level, the ATR-1a operates in one of two modes, Program Mode
or Song Mode. Which mode you use depends upon your application and,
to some extent, how radical are the required corrections.

Program Mode

In Program Mode, you call up one of the ATR-1a’s 50 individual Programs
to control the correction algorithm. Each Program consists of a Scale, a
Speed setting and Vibrato settings. You can step through Programs with a
foot switch or via MIDI.

Use Program Mode when a single scale (or maybe two) is all that’s required
for a particular correction.

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If a performance is quite close to begin with and only requires minor
correction (i.e., never more that 50 cents), it’s often sufficient to simply
choose the Chromatic scale, set Speed to about 10 and leave it there.

If you are working in the studio to correct an already recorded track, you
might use Program Mode to deal with the track one section at a time,
stoping to change Programs between sections.

Song Mode

Song Mode offers a more elaborate set of controls primarily designed to
facilitate the use of the ATR-1a in a live performance situation, whether in
actual concert or during tracking in the studio.

The ATR-1a provides 20 Songs. For each Song, you can program a series of
up to 15 Song Steps. Each Step can contain a Program (with associated
scale) or one of a number of navigation controls (See Chapter 4 for
details). In performance you move from Song Step to Song Step via the
foot switch or MIDI. You can also call up different Songs via MIDI Program
Change messages.

Each Song also contains its own Speed and Vibrato settings that override
those settings in the individual Programs. In this way, an individual
Program’s scale can be used in any number of songs, each with different
Speed and Vibrato settings. (To accomplish the same thing in Program
Mode would require you to create multiple Programs, each with the
identical scale but with the different Speed and Vibrato settings. Very
inefficient. )

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There is of course no hard and fast rule for which mode to use in any
particular situation. Try out both modes and use what feels comfortable
to you.

Chapter 2:
Setting Up the ATR-1a

Setting up the ATR-1a is a very straightforward.

1. Find a suitable location. The ATR-1a is designed to be mounted in a
standard 19-inch equipment rack.

2. Confirm that the included power supply is correct for the electricity in
your part of the world. If you are not sure, or the power supply has a
plug that is incompatible with your wall sockets, contact your local
Antares dealer for help.

Important! Do not attempt to modify the supply or use any other supply that is not

specifically intended for the ATR-1a.

3. First, connect the power supply’s 7-pin DIN connector to the AC INPUT
jack on the rear of the ATR-1a. Then plug the power supply into an AC
outlet.

4. Connect a balanced or unbalanced audio input to one of the INPUT
jacks (see Chapter 4 for details).

5. Connect a cable to one of the OUTPUT jacks and route the output as
appropriate for your application.

6. If you will be controlling your ATR-1a via MIDI, connect a MIDI cable
from your MIDI source to the ATR-1a’s MIDI IN jack.

An Important Note: Unless you plan to be defining the ATR-1a’s target
pitches via MIDI, be sure that MIDI NOTE MODE is set to OFF in the System
Edit pages (see page 29 for details). If MIDI NOTE MODE is set to ON and
no MIDI note data is present, the ATR-1a will pass through all audio
unprocessed, regardless of the settings of the Program Scale Page —
giving the impression that the ATR-1a is not functioning.

An Important Note About Grounding: The ATR-1a is an extremely quiet piece
of gear. When properly connected and grounded, noise and hum will be
inaudible. However, as you’re no doubt well aware, every studio has its own
unique quirks when it comes to connections, grounding and noise. For the
absolute best sonic performance, ensure that your input and output are fully
balanced.

15

An Important Note About Monitoring: If the ATR-1a is used to pitch-

correct an artist’s performance in real time, it is very important that the
performer is able to monitor their original signal, not the pitch-corrected
signal. Trying to react musically to the processed signal will drive them
crazy and, in most cases, drive them farther off pitch.

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Chapter 3:
Panel Controls and Connectors

As you have almost certainly noticed, the ATR-1a has relatively few controls.
We’ll cover them here.

1 2

3 4 5 6 7 8 9

The Front Panel

1 Non-existent Power Switch That’s right. There isn’t one. The ATR-1a is

designed to remain on continuously. You can, of course, plug it in to a
switched power strip or power conditioner if you like, but leaving it on
all the time will do it no harm.

10

2 LCD An easy-to-read 20 character by 2 line display. You can set the

optimum viewing angle in the System menu (See Chapter 4).

3 Data Entry Knob As the name implies, turn it to enter data.
4 CURSOR Buttons The cursor buttons let you move the cursor in the LCD

display from field to field so that you can change the field’s value using
the knob.

5 PROGRAMS Button Press this button to edit a Program or Song. It is

state-sensitive. That is, if you are in Program Mode when you press this
button, you will be taken to the Program Edit pages. If you are in Song
Mode, you will be taken to the Song Edit pages. The accompanying LED
lights to remind you that you are in an edit mode. When the LED is lit,
press the PROGRAMS buttom again to exit the Program Mode.

6 PAGE Button While in Program, Song or System Edit Mode, press this

button to cycle sequentially through the available edit pages. You can
only move in one direction, but there are so few pages in each mode
that you are never more than a few presses away from where you want
to be.

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