Alesis IO|2 Technical document

24-bit USB Audio/MIDI Interface
Quick Start Owner’s Manual
Manual de inicio rápido para el usuario
Manuel d’utilisation du propriétaire
Kurzbedienungsanleitung
Manuale rapido di utilizzo
CONTENIDO DE LA CAJA
•INTERFAZ DE AUDIO/MIDI USB IO|2
•CABLE USB
•MANUAL DE INICIO RÁPIDO DEL USUARIO
•INSTRUCCIONES IMPORTANTES DE SEGURIDAD
INHALT DER VERPACKUNG
•IO|2 USB AUDIO/MIDI INTERFACE
•USB KABEL
•KURZBEDIENUNGSANLEITUNG
•WICHTIGE SICHERHEITSHINWEISE
CONTENUE DE LA BOÎTE
•IO|2 AVEC INTERFACE USB AUDIO/MIDI
•CÂBLE USB
•GUIDE D’UTILISATION SIMPLIFIÉ
•CONSIGNES DE SÉCURITÉ
BOX CONTENTS
•IO|2 USB AUDIO/MIDI INTERFACE
•USB CABLE
•QUICK START OWNER’S MANUAL
•IMPORTANT SAFETY INSTRUCTIONS
CONTENUTO DELLA CONFEZIONE
•INTERFACCIA AUDIO/MIDI IO|2 USB
•CAVO USB
•MANUALE RAPIDO DI UTILIZZO
•IMPORTANTI ISTRUZIONI DI SICUREZZA

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1
IO|2
Quick Start User’s Guide
(English)

2
Introduction
Congratulations on your purchase of the Alesis IO|2 audio/MIDI interface!
We’re proud of this interface and we’ve taken a great deal of care in making the
IO|2 the best sounding, most rugged and easy to use audio interface on the
market.
We’ve made this quick start guide as short as possible, but please read it carefully.
It will guide you through the installation process as well as teach you how to get
the most out of your IO|2 interface.
We hope the IO|2 will serve you well for many years.
Sincerely,
The People of Alesis

3
Key Features
Your IO|2 features the following:
•24-bit recording and playback
•Balanced XLR and ¼” inputs with adjustable gain
•Switchable phantom power
•TRS inserts
•High quality mic preamps
•Comprehensive 4-segment input metering
•Low latency ASIO/WDM/Core Audio drivers
•Zero-Latency monitoring
•MIDI and S/PDIF inputs and outputs
•Headphone out with separate volume knob
•Bus powered for operation without power supply
•Ultra-rugged and lightweight case that’s built to last
Computer Requirements
Minimum PC Requirements:
•Pentium III 450 MHz Processor
•128 MB RAM
•Available USB 1.1 Port
•Windows XP (with Service Pack 2 installed)
Recommended PC Requirements:
•Pentium 4 or Athlon Processor
•512 MB RAM
•7,200 RPM Hard Disk Drive
•Available USB 1.1 Port
•Windows XP (with Service Pack 2 installed)
Minimum Macintosh Requirements:
•Any Apple computer with native USB support
•Mac OS X “Jaguar” version 10.2 or later
•128 MB RAM
Recommended Macintosh Requirements:
•G4 733-MHz Processor or faster
•7,200 RPM Hard Disk Drive
•Mac OS X “Jaguar” version 10.2 or later
•512 MB RAM
Memory Requirements
The IO|2 requires a minimum
of 128MB of RAM to operate,
but most audio applications
need more than 128MB of
RAM to run smoothly. If your
computer only has 128 MB of
memory and is sluggish while
running audio applications,
try adding memory to
improve performance.

4
Product Registration
Please go to http://www.alesis.com and register your new IO|2.
Registering helps us to keep you up-to-date on any last minute product issues and
driver updates. If you would like, we can also send you information on other
products that might interest you.
By registering with us, you let us know what products you use (or dream about)
and this helps us bring you better products in the future.

5
Top Panel Connections
1. Mic Input - Connect a microphone to this input.
2. Guitar/Line Input- Connect a guitar or line-level
instrument to the IO|2 using this connector. Make
sure the “Mic/Line Guitar” switch (see item #4
below) is set correctly.
3. Input Gain Knob - Set the gain level of each
channel with this knob.
4. Mic/Line or Guitar input select – Lets you select the type of instrument
you’ll be using with the Guitar/Line input (see #2 above). Select “Guitar” for
guitars and basses and “Line” for all line-level sources (synths, DATs, etc.)
5. Insert - The insert jack allows you to insert a compressor, EQ, or any other
signal processor in between IO|2’s preamplifier and the A/D converter.
6. +48v Phantom Power Switch - Phantom power switch allows you to power
condenser microphones requiring 48V phantom power. This switch activates
phantom power on both channels.
7. Headphone Output Jack - Plug your headphones into this jack.
8. Headphone Level Knob - Set your headphone level using this knob.
9. Mono/Stereo Monitoring Switch - Allows you to switch your headphones to
mono. This is useful for zero-latency monitoring situations where you may not
want your inputs panned hard left and hard right in your headphones.
10. Monitor Mix Knob - Blend in any amount of zero-latency signal from your
mic/line inputs with the output of your computer.
11. Digital/Analog Input Switch - Select the IO|2’s input source using this
switch. For normal operation, leave this switch set to “analog.” If this switch is
set to “digital,” the S/PDIF input will become active and the Lo-Z, Hi-Z, and
Insert inputs on the IO|2 will be ignored.
12. Main Level Knob - Set the level of the main outputs of the IO|2.
Audio Inputs
Do not use the Mic and
Guitar/Line inputs at the
same time on one channel.
This may overload the
channel and cause distortion.

6
Back Panel Connections
1. MIDI Out Connector - Use a five-pin MIDI cable to connect the MIDI out of
the IO|2 to the MIDI input of an external MIDI device.
2. MIDI In Connector - Use a five-pin MIDI cable to connect the output of an
external MIDI device to the MIDI IN of the IO|2.
3. Stereo Main Output - Use balanced (TRS) or unbalanced (TS) ¼” cables to
connect the IO|2 to a mixer or powered studio monitors.
4. S/PDIF Out - Use a 110-ohm coaxial cable to connect the S/PDIF output of
your IO|2 to the digital input of another device.
5. S/PDIF In - Connect the digital output of another
device to your IO|2’s S/PDIF input using a 110-ohm
coaxial cable.
6. USB Connector - Use a standard USB cable to
hook up your IO|2 to the USB 1.1 (or higher)
connection on your computer.
Plug the IO|2 directly into
your computer, and avoid
using a USB hub. Hubs can
interfere with the IO|2’s
audio and MIDI timing
signals.

7
Status Lights
1. +48V – Lights up when phantom power is engaged.
2. MIDI Out – Flashes whenever MIDI data is sent out of
the IO|2.
3. MIDI In – Flashes whenever MIDI data is received from
an external MIDI controller.
4. USB – Lights up when a USB connection has been
established with your computer.
5. Stereo 4-segment input meters – Allow you to monitor
incoming levels. See the sidebar on the right for tips on how
to set levels.
Setting Gain Levels
The 4-segment input meters
are there to help you know
how loud your inputs are.
When you are adjusting the
gain knobs for each channel,
try to set your levels as loud
as possible without reaching
“0 dB.” If your input
reaches 0 dB, you are
overloading or “clipping”
the IO|2 and this results in
severe distortion.
Ideally, your levels should
peak between -6 and -3 dB on
the meters.

8
Hookup Diagrams
The following setup will work well for most guitarist/singers:
1. Guitars – Plug guitars into the Guitar/Line input and make sure the “Mic/Line
Guitar” switch is set to “Guitar” to ensure best recording quality.
2. Microphones – Plug microphones into the XLR input of the IO|2. Make sure
that the “Mic/Line Guitar” switch is set to “Mic/Line.” If you are using a
condenser microphone that requires phantom power (most condensers do), turn
on phantom power using the +48V switch.
3. Headphones – Plug your headphones into this jack. The IO|2’s headphone
output can be very loud, so turn the gain up slowly until you reach a level that is
comfortable for you. If you are experiencing distracting “latency delays” of your
guitar or voice, turn the Monitor Mix knob towards “direct” until you find a good
balance between the zero-latency mic inputs and the output of your computer.
4. Main Outputs – The IO|2 supports both balanced “TRS” and unbalanced
“TS” ¼” cables. If your speakers (or mixer) support balanced cables, use them as
they give you better performance and lower noise.
5. USB Cable – Plug in your USB cable directly into your computer and avoid
using a USB hub. Hubs can interfere with audio and MIDI timing signals and
cause problems for the IO|2.
6. Insert – The IO|2 allows you to easily insert an additional processor such as a
reverb or compressor in your recording path. Simply use a TRS to dual-TS “insert
cable” to connect the additional device to the IO|2’s insert jack.

9
The following setup will work well for most keyboard players:
1. Keyboards – Connect the outputs of your keyboard into the “Guitar/Line”
inputs of the IO|2. If your keyboard only has one output, go ahead and connect
to whichever channel of the IO|2 you prefer. When connecting keyboards, be
sure to set the “Mic/Line Guitar” switch to “Mic/Line.”
2. MIDI – If you plan to use a MIDI sequencing program on your computer to
control your keyboard, go ahead and connect the MIDI OUT of your keyboard to
the MIDI IN of the IO|2 and the MIDI OUT of the IO|2 to the MIDI IN of
your keyboard.
3. Headphones – Plug your headphones into this jack. The IO|2’s headphone
output can be very loud, so turn the gain up slowly until you reach a level that is
comfortable for you. If you are experiencing distracting “latency delays” of your
guitar or voice, turn the Monitor Mix knob towards “direct” until you find a good
balance between the zero-latency mic inputs and the output of your computer.
4. Main Outputs – The IO|2 supports both balanced “TRS” and unbalanced
“TS” ¼” cables. If your speakers (or mixer) support balanced cables, use them as
they give you better performance and lower noise.
5. USB Cable – Plug in your USB cable directly into your computer and avoid
using a USB hub. Hubs can interfere with audio and MIDI timing signals and
cause problems for the IO|2.

10
Plug-and-Play Connection to a Computer
Both Windows XP and Mac OS X see the IO|2 as a
plug-and play device. No installation is necessary on
Mac OS 10.2—Just connect the USB cable and you’re
ready to go. Driver installation is not required on
Windows XP since the IO|2 supports the default audio
drivers, but we highly recommend installing the Alesis
audio drivers. Our drivers will yield significantly lower
latency and better performance.
To install the IO|2 on Windows XP, simply insert the
supplied Alesis CD-ROM and wait for the following menu to pop up:
Click “Install Alesis Audio Driver,” to proceed with the driver
installation. During the installation process, Windows XP will
prompt you with the following warning:
Press “Continue Anyway,” to finish the installation. Restart the machine as the
software recommends. Once your computer is restarted, your IO|2 is ready to
record.
The IO|2 is not compatible
with earlier versions of
Windows or Mac OS.
Check http://www.Alesis.com
for driver updates and last
minute issues regarding the
IO|2
SysEx Transfers
When performing large
SysEx transfers over
Windows, you may need to
increase the buffer size on
your Windows software.
Otherwise, Windows may
process the transfer
incorrectly. Selecting a
buffer size equal to or larger
than the SysEx file virtually
assures that the transfer will
occur without errors.

11
Troubleshooting:
Symptom Cause Solution
USB light does not
turn on.
The IO|2 is not
receiving power or
USB connection is
not being made to
your computer
Make sure you are connecting your IO|2
directly to your computer’s USB connector and
not into a USB hub. If this does not solve the
problem, double check your driver installation
and verify that the IO|2’s drivers have been
installed properly. If the problem persists, the
cable may be faulty. Try using another USB
cable.
Input meters are not
responding
The digital/analog
input switch may be
set incorrectly
Make sure the input switch is set to “analog” if
you are recording using the XLR and 1/4”
inputs on the top of the IO|2. Only set this
switch to “digital” if you want to use the
S/PDIF connectors.
S/PDIF I/O is not
working
The digital/analog
input switch may be
set incorrectly
If you plan to use S/PDIF connections to
transfer audio digitally, make sure the input
switch is set to “digital.” Otherwise, leave this
switch set to “analog” for normal operation.
The input switch is set
to “Analog” but my
incoming signal is still
not present (or it is
very soft).
Your phantom
power or mic/line
switches may not be
set correctly
Double check that the mic/line switch is set
correctly for each channel. If you’re using
condenser microphones that require phantom
power, turn on the +48v phantom power
switch. Finally, make sure the gain knob is
turned up.
My S/PDIF inputs
and outputs just put
out clicks, pops, or
white noise
Your coaxial cables
are not 110-ohm.
It is very important to use 110-ohm coaxial
cables for all S/PDIF connections. Most plain
RCA cables are NOT 110-ohm and cause
clocking problems between two digital devices.
This causes loud clicks, pops, and sustained
white noise.

12
Specifications
Interface: IO|2 24-bit audio/MIDI interface
Features: Stereo, 24-bit inputs and outputs. Sample-rate
adjustable up to 48 kHz. Separate gain knob and
mic/line switch for each input. All balanced inputs
and outputs. Stereo ¼” headphone jack. S/PDIF
and MIDI I/O.
Audio I/O: Mic/line inputs
SNR 95dB (A-weighted) minimum -- 97dB typical
THD+N 0.007% maximum -- 0.005% typical
freq response +/-0.35dB typ
1/4" guitar inputs
SNR 94dB (A-weighted) minimum -- 96dB typical
THD+N 0.05% maximum -- 0.034% typical
freq response +/-1.2dB
Analog outputs
SNR 95dB (A-weighted) minimum -- 97dB typical
THD+N 0.007% maximum -- 0.005% typical
freq response +/-0.35dB typ
Software: Ultra-low latency ASIO/WDM drivers for
Windows XP. Full support for Core Audio on
Mac OS X.
Power options: USB bus power
Dimensions: 6.5” x 4.7” x 2.25” / 16.5 cm x 12.0 cm x 5.8 cm
Weight (net): 1.5 lbs / 0.68 kg

13
IO|2
Guía de inicio rápido del usuario
(Español)

14
Introducción
¡Felicitaciones por su compra de la interfaz de audio/MIDI Alesis IO|2! Estamos
orgullosos de esta interfaz y hemos tomado los mejores recaudos para hacer que la
IO|2 sea la interfaz de audio más sonora, robusta y fácil de usar del mercado.
Hemos hecho esta guía de inicio rápido lo más breve posible, pero léala
detenidamente. Lo guiará a través del proceso de instalación y le enseñará cómo
obtener los mejores resultados de su interfaz IO|2.
Esperamos que la IO|2 le brinde un buen servicio por muchos años.
Atentamente
La Gente de Alesis

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Características principales
Su interfaz IO|2 ofrece lo siguiente:
•Grabación y reproducción en 24 bits
•Entradas XLR y de ¼” balanceadas con ganancia ajustable
•Alimentación fantasma conmutable
•Inserciones TRS
•Preamplificadores de micrófono de alta calidad
•Medición completa de la entrada con 4 segmentos
•Drivers ASIO/WDM/Core Audio de baja latencia
•Monitoreo con cero latencia
•Entradas y salidas MIDI y S/PDIF
•Salida para auriculares con perilla de volumen independiente
•Alimentación por bus para operación sin fuente de alimentación
•Carcasa ultra robusta y liviana construida para durar
Requisitos de computadora
Requisitos mínimos de PC:
•Procesador Pentium III de 450 MHz
•128 MB de RAM
•Puerto USB 1.1 disponible
•Windows XP (con Service Pack 2 instalado)
Requisitos de PC recomendados:
•Procesador Pentium 4 o Athlon
•512 MB de RAM
•Disco duro de 7,200 RPM
•Puerto USB 1.1 disponible
•Windows XP (con Service Pack 2 instalado)
Requisitos mínimos de Macintosh:
•Cualquier computadora Apple con soporte de USB
nativo
•Mac OS X “Jaguar” versión 10.2 o posterior
•128 MB de RAM
Requisitos de Macintosh recomendados:
•Procesador G4 de 733 MHz o más rápido
•Disco duro de 7,200 RPM
•Mac OS X “Jaguar” versión 10.2 o posterior
•512 MB de RAM
Requisitos de memoria
La interfaz IO|2 requiere un
mínimo de 128 MB de RAM
para operar, pero la mayoría
de las aplicaciones de audio
requieren más de 128 MB de
RAM para funcionar
correctamente. Si su
computadora tiene sólo 128
MB de memoria y es lenta
para ejecutar aplicaciones de
audio, pruebe agregar
memoria para mejorar el
rendimiento.

16
Registración del producto
Vaya a http://www.alesis.com y registre su nueva interfaz IO|2.
La registración nos ayuda a mantenerlo actualizado acerca de las novedades de
última hora sobre el producto y las actualizaciones de los drivers. Si desea,
también podemos enviarle información de otros productos que le puedan
interesar.
Al registrarse con nosotros, usted nos hace saber qué productos usa (o con qué
productos sueña) y eso nos ayuda a ofrecerle mejores productos en el futuro.

17
Conexiones del panel superior
1. Entrada XLR de micrófono – Conecte un
micrófono al IO/2 usando esta entrada.
2. Entrada de guitarra o instrumento – Conecte
una guitarra o instrumento al IO/2 usando este
conector. Asegúrese de que el switch de“Mic/Line
Guitar” (ver # 4) esté correctamente instalado.
3. Perilla de ganancia de entrada – Ajuste con esta
perilla el nivel de ganancia de cada canal.
4. Mic/Line o Guitar input select – Le permite elegir el tipo de instrumento a
utilizar con el “Guitar line input” (ver # 2 arriba). Seleccione “Guitar” para
guitarras y bajos, y “Line” para todas las otras fuentes niveladas como
(sintetizadores, DATs, etc).
5. Inserción – El conector de inserción permite insertar un compresor, un
ecualizador o cualquier otro procesador de señal entre el preamplificador y el
conversor A/D de la interfaz IO|2.
6. Interruptor de alimentación fantasma de +48 V – La alimentación fantasma
le permite alimentar los micrófonos de condensador que requieren esta
alimentación. Este interruptor activa la alimentación fantasma en ambos canales.
7. Conector de salida para auriculares – Enchufe sus auriculares en este
conector.
8. Perilla de nivel de auriculares – Ajuste el nivel de sus auriculares usando esta
perilla.
Entradas de audio
No utilice la entrada de
micrófono y guitarra ( Mic
and Guitar/line ) al mismo
tiempo en el mismo canal.
Esto puede saturar el canal y
causar distorsión.

18
9. Conmutador de monitoreo mono/estéreo – Le permite conmutar sus
auriculares a mono. Este conmutador es útil para situaciones de monitoreo con
latencia cero en las que no es conveniente que sus entradas se desplacen
fuertemente a izquierda y derecha en sus auriculares.
10. Perilla de mezcla de monitor – Combine cualquier valor de señal de latencia
cero de sus entradas de micrófono/línea con la salida de su computadora.
11. Conmutador de entrada digital/analógica – Seleccione la fuente de entrada
de la interfaz IO|2 usando este conmutador. Para operación normal, deje este
conmutador en posición “analógica”. Si este conmutador se coloca en “digital,” se
activará la entrada S/PDIF y se ignorarán las entradas de baja impedancia, alta
impedancia e inserción de la interfaz IO|2.
12. Perilla de nivel principal – Ajuste el nivel de las entradas principales de la
interfaz IO|2.