Alesis MULTIMIX12R User Manual

MIXER / MICROPHONE PREAMPLIFIER

REFERENCE

MANUAL

2002

Important Safety

Instructions

Important Safety Instructions
(English)

Safety symbols used in this product

operating and maintenance instructions in the literature
accompanying this unit.

the unit that can cause dangerous electric shocks.

voltages that can cause dangerous electrical shock.

Please follow these precautions
when using this product:

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Do not use this apparatus near water.

6. Clean only with a damp cloth. Do not spray any liquid cleaner

7. Install in accordance with the manufacturer's instructions.

8. Do not install near any heat sources such as radiators, heat

9. Do not defeat the safety purpose of the polarized or

10. Protect the power cord from being walked on or pinched,

11. Use only attachments or accessories specified by the

This symbol alerts the user that there are important

This symbol warns the user of uninsulated voltage within

This symbol warns the user that output connectors contain

onto the faceplate, as this may damage the front panel controls
or cause a dangerous condition.

registers, stoves, or other apparatus (including amplifiers) that
produce heat.

grounding-type plug. A polarized plug has two blades with
one wider than the other. A grounding-type plug has two
blades and a third grounding prong. The wide blade or the
third prong are provided for your safety. When the provided
plug does not fit into your outlet, consult an electrician for
replacement of the obsolete outlet.

particularly at plugs, convenience receptacles, and the point
where they exit from the apparatus.

manufacturer.

Important Safety Instructions

12. Use only with a cart, stand, bracket, or table designed for use
with professional audio or music equipment. In any
installation, make sure that injury or damage will not result
from cables pulling on the apparatus and its mounting. If a
cart is used, use caution when moving the cart/apparatus
combination to avoid injury from tip-over.

13. Unplug this apparatus during lightning storms or when unused
for long periods of time.

14. Refer all servicing to qualified service personnel. Servicing is
required when the apparatus has been damaged in any way,
such as when the power-supply cord or plug is damaged, liquid
has been spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture, does not
operate normally, or has been dropped.

15. This unit produces heat when operated normally. Operate in a
well-ventilated area with at least six inches of clearance from
peripheral equipment.

16. This product, in combination with an amplifier and
headphones or speakers, may be capable of producing sound
levels that could cause permanent hearing loss. Do not
operate for a long period of time at a high volume level or at a
level that is uncomfortable. If you experience any hearing loss
or ringing in the ears, you should consult an audiologist.

17. Do not expose the apparatus to dripping or splashing. Do not
place objects filled with liquids (flower vases, soft drink cans,
coffee cups) on the apparatus.

18. WARNING: To reduce the risk of fire or electric shock, do
not expose this apparatus to rain or moisture.

Important Safety Instructions

Instructions de Sécurité Importantes
(French)

Symboles utilisés dans ce produit

Ce symbole alèrte l’utilisateur qu’il existe des instructions
de fonctionnement et de maintenance dans la documentation
jointe avec ce produit.

Ce symbole avertit l’utilisateur de la présence d’une
tension non isolée à l’intérieur de l’appareil pouvant engendrer des
chocs électriques.

Ce symbole prévient l'utilisateur de la présence de tensions
sur les raccordements de sorties, représentant un risque
d'électrocution.

Veuillez suivre ces précautions
lors de l’utilisation de
l’appareil:

1. Lisez ces instructions.

2. Gardez ces instructions.

3. Tenez compte de tous les avertissements.

4. Suivez toutes les instructions.

5. N’utilisez pas cet allareil à proximité de l’eau.

6. Ne nettoyez qu’avec un chiffon humide. Il est potentiellement

dangereux d'utiliser des pulvérisateurs ou nettoyants liquides
sur cet appareil.

7. Installez selon les recommandations du constructeur.

8. Ne pas installer à proximilé de sources de chaleur comme

radiateurs, cuisinière ou autre appareils (don’t les
amplificateurs) produisant de la chaleur.

9. Ne pas enlever la prise de terre du cordon secteur. Une prise

murale avec terre deux broches et une troisièrme reliée à la
terre. Cette dernière est présente pour votre sécurité. Si le
cordon secteur ne rentre pas dans la prise de courant,
demandez à un électricien qualifié de remplacer la prise.

10. Evitez de marcher sur le cordon secteur ou de le pincer, en

particulier au niveau de la prise, et aux endroits où il sor de
l’appareil.

11. N’utilisez que des accessoires spécifiés par le constructeur.

Important Safety Instructions

Suite de la page suivante

12. N’utilisez qu’avec un stand, ou table conçus pour l’utilisation

d’audio professionnel ou instruments de musique. Dans toute
installation, veillez de ne rien endommager à cause de câbles
qui tirent sur des appareils et leur support.

13. Débranchez l’appareil lors d’un orage ou lorsqu’il n’est pas

utilisé pendant longtemps.

14. Faites réparer par un personnel qualifié. Une réparation est

nécessaire lorsque l’appareil a été endommagé de quelque sorte
que ce soit, par exemple losrque le cordon secteur ou la prise
sont endommagés, si du liquide a coulé ou des objets se sont
introduits dans l’appareil, si celui-ci a été exposé à la pluie ou à
l’humidité, ne fonctionne pas normalement ou est tombé.

15. Puisque son fonctionement normale génère de la chaleur,

placez cet appareil au moins 15cm. des équipments
péripheriques et assurez que l’emplacement permet la
circulation de l’air.

16. Ce produit, utilisé avec un amplificateur et un casque ou des

enceintes, est capable de produite des niveaux sonores pouvant
engendrer une perte permanente de l’ouïe. Ne l’utilisez pas
pendant longtemps à un niveau sonore élevé ou à un niveau
non confortable. Si vous remarquez une perte de l’ouïe ou un
bourdonnement dans les oreilles, consultez un spécialiste.

17. N'exposez pas l'appareil à l'égoutture ou à l'éclaboussement.

Ne placez pas les objets remplis de liquides (vases à fleur,
boîtes de boisson non alcoolique, tasses de café) sur l'appareil.

18. AVERTISSEMENT: Pour réduire le risque du feu ou de

décharge électrique, n'exposez pas cet appareil à la pluie ou à
l'humidité.

Important Safety Instructions

Lesen Sie bitte die folgende Sicherheitshinweise
(German)

Sicherheit Symbole verwendet in
diesem Produkt

Dieses Symbol alarmiert den Benutzer, daß es wichtige
Funktionieren und Wartung Anweisungen in der Literatur gibt, die
diese Maßeinheit begleitet.

Dieses Symbol warnt den Benutzer der nicht isolierten
Spannung innerhalb der Maßeinheit, die gefährliche elektrische
Schläge verursachen kann.

Dieses Symbol warnt den Benutzer, dem Ausgabestecker
Spannungen enthalten, die gefährlichen elektrischen Schlag
verursachen können.

Folgen Sie bitte diesen
Vorkehrungen, wenn dieses Produkt
verwendet wird:

1. Lesen Sie die Hinweise.

2. Halten Sie sich an die Anleitung.

3. Beachten Sie alle Warnungen.

4. Beachten Sie alle Hinweise.

5. Bringen Sie das Gerät nie mit Wasser in Berührung.

6. Verwenden Sie zur Reinigung nur ein weiches Tuch.

Verwenden Sie keine flüssigen Reinigungsmittel. Dies kann
gefährliche Folgen haben.

7. Halten Sie sich beim Aufbau des Gerätes an die Angaben des

Herstellers.

8. Stellen Sie das Gerät nich in der Nähe von Heizkörpern,

Heizungsklappen oder anderen Wärmequellen (einschließlich
Verstärkern) auf.

9. Verfehlen Sie nicht den Zweck des grounging Terminals auf

dem Netzstecker. Dieses Terminal wird für Ihre Sicherheit zur
Verfügung gestellt.

10. Verlegen Sie das Netzkabel des Gerätes niemals so, daß man

darüber stolpern kann oder daß es gequetscht wird.

11. Benutzen Sie nur das vom Hersteller empfohlene Zubehör.

Important Safety Instructions

Fortsetzung auf nächster Seite

12. Verwenden Sie ausschließlich Wagen, Ständer, oder Tische, die

speziell für professionelle Audio- und Musikinstrumente
geeignet sind. Achten Sie immer darauf, daß die jeweiligen
Geräte sicher installiert sind, um Schäden und Verletzungen zu
vermeiden. Wenn Sie einen Rollwagen benutzen, achten Sie
darauf, das dieser nicht umkippt, um Verletzungen
auszuschließen.

13. Ziehen Sie während eines Gewitters oder wenn Sie das Gerät

über einen längeren Zeitraum nicht benutzen den Netzstecher
aus der Steckdose.

14. Die Wartung sollte nur durch qualifiziertes Fachpersonal

erfolgen. Die Wartung wird notwendig, wenn das Gerät
beschädigt wurde oder aber das Stromkabel oder der Stecker,
Gegenstände oder Flüssigkeit in das Gerät gelangt sind, das
Gerät dem Regen oder Feuchtigkeit ausgesetzt war und
deshalb nicht mehr normal arbeitet oder heruntergefallen ist.

15. Dieses Gerät produziert auch im normalen Betrieb Wärme.

Achten Sie deshalb auf ausreichende Lüftung mit mindestens
15 cm Abstand von anderen Geräten.

16. Dieses Produkt kann in Verbindung mit einem Verstärker und

Kopfhörern oder Lautsprechern Lautstärkepegel erzeugen, die
anhaltende Gehörschäden verursachen. Betreiben Sie es nicht
über längere Zeit mit hoher Lautstärke oder einem Pegel, der
Ihnen unangenehm is. Wenn Sie ein Nachlassen des Gehörs
oder ein Klingeln in den Ohren feststellen, sollten Sie einen
Ohrenarzt aufsuchen.

17. Setzen Sie den Apparat nicht Bratenfett oder dem Spritzen

aus. Plazieren Sie die Nachrichten, die mit Flüssigkeiten
(gefüllt werden Blumevases, Getränkdosen, Kaffeetassen)
nicht auf den Apparat.

18. WARNING: um die Gefahr des Feuers oder des elektrischen

Schlages zu verringern, setzen Sie diesen Apparat nicht Regen
oder Feuchtigkeit aus.

Important Safety Instructions

CE Declaration Of Conformity

See our website at:

http://www.alesis.com

FCC Compliance Statement

This device complies with Part 15 of the FCC rules. Operation is
subject to the following two conditions: (1) This device may not
cause harmful interference and (2) this device must accept any
interference received, including interference that may cause
undesired operation.

NOTE: This equipment has been tested and found to comply with
the limits for a Class B digital device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a residential installation.
This equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the
instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference
will not occur in a particular installation. If this equipment does
cause harmful interference to radio or television reception, which
can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or more of
the following measures:

-- Reorient or relocate the receiving antenna.

-- Increase the separation between the equipment and receiver.

-- Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.

-- Consult the dealer or an experienced radio/TV technician for
help.

5

Stereo Aux

Return Level

Phones/Monitor

Level

Monitor Select

Switch

Master LevelPhantom Power

Indicator

Gain

Headphone JackMaster Fader

Microphone In

Stereo Aux Return

Channel Fader

Channel

Pan/Balance

Monitor Out Line In Channel Insert

Main Out

Aux Sends

Main Out

W MAX

Tape Monitor In

FRONT PANEL

High Frequency EQ

Low Frequency EQ

Aux Send 1

(Pre Fader)

Aux Send 2

(Post Fader)

Power Switch

Power In

Phantom Power Switch

REAR PANEL

Introduction

TABLE OF CONTENTS

Table of Contents ................................................................. 1

Introduction............................................................................. 3

The Alesis Multimix 12R Microphone Preamplifier/Mixer........................3

Using this manual.............................................................................................3

Grounding Instructions...................................................................................4

Installation ............................................................................... 5

Unpacking .........................................................................................................5

AC power.......................................................................................................... 5

Grounding.............................................................................................5

Use clean power ...................................................................................6

Power switch.........................................................................................6

Mounting...........................................................................................................6

Connections ............................................................................. 7

Inputs .................................................................................................................7

Cable common sense...........................................................................7

Microphone Inputs...............................................................................8

Phantom power....................................................................................9

Line-level devices (synthesizers, CD players, video)....................10

TAPE IN jacks .....................................................................................12

Phonograph turntables .....................................................................13

Do not connect any of the following to any input of the

Multimix 12R!......................................................................................13

How to connect effect devices and signal processors...............................14

Effects via Aux Send and Aux Return .............................................14

In-line processing using the INSERT jacks (compressors &

equalizers) ...........................................................................................15

Outputs ............................................................................................................18

To a stereo PA system or instrument amplifier ............................18

To a mono system..............................................................................18

To a stage monitor (foldback) system ............................................18

To another mixer................................................................................19

To a stereo tape recorder.................................................................. 19

To an ADAT multitrack recorder.....................................................20

Phones..................................................................................................23

Monitor Out ........................................................................................23

Operating Instructions...................................................... 25

Before turning the mixer on, "zero out' the controls................................25

Setting input trim levels ................................................................................26

PEAK LED method ............................................................................26

Metering/Unity Gain method..........................................................27

Typical Fader and Control Levels................................................................28

Proper gain staging of other equipment........................................ 29

Multimix 12R Reference Manual 1

Introduction

AUX System: Effects Send/Receive............................................................30

How to Set Aux Send and Return Levels .......................................30

Using the meter.............................................................................................. 32

Avoiding noise................................................................................................33

System noise (ground loops, hum, induced noise)....................... 33

Applications...........................................................................37

Multitrack recording......................................................................................37

Tracking/Overdubbing.....................................................................37

Mixdown..............................................................................................38

Using the HIGH and LOW EQ controls......................................................39

Monitoring AUX 1 in the PHONES jack .....................................................40

Troubleshooting...................................................................4 1

Troubleshooting Index.................................................................................. 41

Maintenance/Service.....................................................................................43

Exterior cleaning.................................................................................43

Specifications ....................................................................... 45

Frequency Response......................................................................................45

Connectors...................................................................................................... 45

Levels ...............................................................................................................46

Impedance.......................................................................................................46

Noise performance (typical)......................................................................... 47

Distortion (THD+N).......................................................................................47

Power............................................................................................................... 47

Mounting.........................................................................................................47

Dimensional Drawing ....................................................... 48

Block diagram ..................................................................... 49

Level diagram.................................................................................................50

Index ........................................................................................ 51

Introduction

INTRODUCTION

The Alesis Multimix 12R Microphone
Preamplifier/Mixer

The Alesis Multimix 12R is a high-quality, rack-mountable 12-input,
stereo output audio mixer. It is designed to handle eight microphones,
two stereo line inputs, and to route signal to and from external effect
processing devices. As a basic, easy-to-understand mixer, it can be
used in a wide variety of applications from sound reinforcement to
multitrack recording. It may also be used as an accessory or submixer
to a larger console.

Using this manual

To get the most out of your Multimix 12R, please read this manual.
While the mixer is not complicated to operate, the manual contains
information that will help you get the highest level of performance
from it. We’ve included creative alternative techniques that aren't
obvious at first glance.

To find what you need quickly, refer to the index at the back of the
manual, or the Table of Contents.

Conventions

The buttons, knobs, and rear panel connectors are referred to in this
manual just as their names appear on the Multimix 12R, using all
capital letters (Example: [TRIM] control, [PAN] knob, [PHONES] jack,
etc.).

✪ When something important appears in the manual, an icon (like the one on the

left) will appear in the left margin. This symbol indicates that this information
is vital when operating the Multimix 12R.

Multimix 12R Reference Manual 3

Introduction

Grounding Instructions

This product must be grounded. If it should malfunction or break
down, grounding provides a path of least resistance for electric current
to reduce the risk of electric shock. This product is equipped with a
cord having an equipment-grounding conductor and a grounding
plug. The plug must be plugged into an appropriate outlet that is
properly installed and grounded in accordance with all local rules and
ordinances.

DANGER - Improper connection of the equipment-grounding conductor
can result in a risk of electric shock. Check with a qualified electrician or
serviceman if you are in doubt as to whether the product is properly
grounded. Do not modify the plug provided with the product; if it will not fit
the outlet, have a proper outlet installed by a qualified electrician.

Unpacking

The Multimix 12R box should contain:

1. The mixer itself

2. A packet of literature along with this manual

3. An AC power cable

AC power

READ ALL SAFETY WARNINGS IN THE PREVIOUS SECTION OF
THIS MANUAL TO ENSURE SAFE OPERATION OF THIS UNIT.
Connect the Multimix 12R to the specified power using the AC cable
supplied with the unit. The AC cable is removable. If the distance to
your AC outlet is longer or shorter than the supplied cable, you may
substitute an approved standard NEMA-to-CEE power cable of the
correct length, available from most electronics stores.

Grounding

CONNECT THE MULTIMIX 12R TO A PROPERLY GROUNDED
OUTLET ONLY. DO NOT USE ADAPTERS WHICH REMOVE THE
SAFETY GROUND PROTECTION OR CUT OFF THE GROUNDING
PRONG ON THE POWER CORD. Proper grounding is essential for
user safety and low noise. If you experience 60-cycle hum in your
sound system as a result of different ground potentials between
different units in your system, plug all units into the same AC circuit (if
the total power load allows) and make sure other devices in the
system are properly grounded themselves. The Multimix 12R features
balanced inputs and outputs, so if it is properly connected to other
balanced units, AC ground potentials will not affect the audio. If you
cannot get rid of ground loops, consult a professional electrician
familiar with sound system power designs.

Installation

INSTALLATION

Multimix 12R Reference Manual 5

Installation

Use clean power

The Multimix 12R's internal power supply is designed to filter out most
AC line noise. However, it is still good practice to plug your sound
equipment into an AC circuit that is not shared with lighting dimmers,
refrigerators, air conditioning units, or other appliances that may
induce noise into the power system.

Power switch

The POWER switch is located on the back panel. A power indicator is
on the front panel next to the meter. Avoid turning the power switch
on or off while the Multimix 12R is connected to a live amplifier.

Mounting

The Multimix 12R may be rack mounted in a standard EIA 19" rack,
occupying three standard 1.75" rack spaces. Any angle of orientation is
acceptable. Note that (as with most audio equipment) if it is mounted
into metal rack rails, the chassis ground of all units in the rack will be
connected together by the rail. In some cases this is desirable, but if
hum is a problem in the system, you may need to install non­conductive rack screws and washers on the Multimix 12R or other
equipment in the rack to isolate the chassis grounds from each other.

The mixer may also be used on a table top. To avoid scratching a
tabletop surface, apply rubber or felt feet to the bottom of the
Multimix 12R.

Inputs

Cable common sense

Make all connections to the Multimix 12R with the power turned off

wherever possible. If you must connect or disconnect inputs while
power is on, make sure the channel fader and [TRIM] are turned all the
way down to avoid sudden pops and clicks which may damage
speakers or other equipment.

Use good-quality cable: 99% of all mixer problems turn out to be
cable or connector problems. Use the best quality cable you can, for
highest reliability and lowest noise. If something goes wrong, check
the cable and its connection to the mixer first. If the connectors are
dirty or corroded, clean them with isopropyl alcohol or other
approved electrical contact cleaner before inserting them into the
Multimix 12R. High quality cables are low-capacitance shielded cables
with a stranded (not solid) internal conductor and a low-resistance
shield. Although quality cables cost more, they do make a difference.

Route cables in your system correctly by observing the following
precautions:

• Do not bundle audio cables with AC power cords.

• Avoid running audio cables, or placing the Multimix 12R itself,

Connections

CONNECTIONS

near sources of electromagnetic interference such as transformers,
monitors, computers, etc.

• Never unplug a cable by pulling on the wire itself. Always unplug

by firmly grasping the body of the plug and pulling directly
outward.

• Do not place cables where they can be stepped on. Stepping on a

cable may not cause immediate damage, but it can compress the
insulation between the center conductor and shield (degrading
performance), or reduce the cable’s reliability.

• Avoid twisting the cable or having it make sharp, right angle turns.

Multimix 12R Reference Manual 7

Connections

Microphone Inputs

The Alesis Multimix 12R features eight studio-grade, low-noise hybrid
microphone preamplifiers. These [MIC] jacks are designed to work
with almost any low-impedance microphone using standard 3­conductor XLR connectors. The [MIC] jacks also feature 48 volt
phantom power, which may be turned on and off by the [PHANTOM]
switch on the back panel, for condenser microphones which require
external powering.

Balanced Mic Input

Hot

12

3

Cold

Socket (female)

Ground

The MIC Input is designed to accept a wide range of balanced or
unbalanced low impedance input signals, with up to 60 dB of
amplification available (which is 10 to 20 dB more than many other
rack-mount mixers). It is wired with "pin 2 hot" according to the
accepted standard.

✪ Use only one input per channel. The LINE IN jack and the MIC IN

jack of a channel can’t be used at the same time. If you turn up the
level of a line source to hear it at the same time a microphone is
connected, you may damage the microphone.

Connections

Phantom power

Certain types of microphones (called condenser microphones) require
a DC power supply from the mixer. “Phantom power” sends 48 volts
of DC through the microphone cable. If any of your microphones
need phantom power, turn on the [PHANTOM POWER] switch on the
Multimix 12R’s back panel to connect all the XLR MIC IN jacks to the
Multimix 12R’s internal 48 volt phantom power source. Since the
power is applied equally to pins 2 and 3, phantom power should not
affect dynamic microphones (which do not require phantom power).
However, make sure that your microphone cables have no short
circuits or intermittent connections to avoid damage to the system.

✪Avoid connecting or disconnecting any microphones while

[PHANTOM POWER] is turned on. Make all connections with the
Multimix 12R powered off. If this is not possible, make sure the
channel's fader and [TRIM] are down, make the connections, then turn
on the [PHANTOM POWER] switch on the back panel before bringing
the fader and [TRIM] back up. Many microphones make a loud "pop"
when first powered, so make sure your faders are down to avoid
damaging your speakers or hearing.

Never connect the MIC jack to an UNBALANCED source or to a line-

level device (such as a tape recorder or synthesizer) when phantom
power is being used.

If none of your microphones need phantom power, leave the
phantom power switch off.

Multimix 12R Reference Manual 9