Extron Electronics MLA VC10 Plus User Manual

MLA VC10 Plus

Volume Control Module

User Guide

Audio

68-1828-01 Rev. C

06 12

Safety Instructions • English

This symbol is intended to alert the user of important operating and
maintenance (servicing) instructions in the literature provided with the
equipment.

This symbol is intended to alert the user of the presence of uninsulated
dangerous voltage within the product enclosure that may present a risk of
electric shock.

Caution

Read Instructions • Read and understand all safety and operating instructions before using the equipment.
Retain Instructions • The safety instructions should be kept for future reference.
Follow Warnings • Follow all warnings and instructions marked on the equipment or in the user information.
Avoid Attachments • Do not use tools or attachments that are not recommended by the equipment

manufacturer because they may be hazardous.

Warning

Power sources • This equipment should be operated only from the power source indicated on the product. This

equipment is intended to be used with a main power system with a grounded (neutral) conductor. The third
(grounding) pin is a safety feature, do not attempt to bypass or disable it.

Power disconnection • To remove power from the equipment safely, remove all power cords from the rear of the

equipment, or the desktop power module (if detachable), or from the power source receptacle (wall plug).

Power cord protection • Power cords should be routed so that they are not likely to be stepped on or pinched by

items placed upon or against them.

Servicing • Refer all servicing to qualified service personnel. There are no user-serviceable parts inside. To prevent

the risk of shock, do not attempt to service this equipment yourself because opening or removing covers may
expose you to dangerous voltage or other hazards.

Slots and openings • If the equipment has slots or holes in the enclosure, these are provided to prevent

overheating of sensitive components inside. These openings must never be blocked by other objects.

Lithium battery • There is a danger of explosion if battery is incorrectly replaced. Replace it only with the same or

equivalent type recommended by the manufacturer. Dispose of used batteries according to the instructions of
the manufacturer.

Consignes de Sécurité • Français

Ce symbole sert à avertir l’utilisateur que la documentation fournie avec le
matériel contient des instructions importantes concernant l’exploitation et la
maintenance (réparation).

Ce symbole sert à avertir l’utilisateur de la présence dans le boîtier
de l’appareil de tensions dangereuses non isolées posant des risques
d’électrocution.

Attention

Lire les instructions• Prendre connaissance de toutes les consignes de sécurité et d’exploitation avant d’utiliser

le matériel.

Conserver les instructions• Ranger les consignes de sécurité afin de pouvoir les consulter à l’avenir.
Respecter les avertissements • Observer tous les avertissements et consignes marqués sur le matériel ou

présentés dans la documentation utilisateur.

Eviter les pièces de fixation • Ne pas utiliser de pièces de fixation ni d’outils non recommandés par le fabricant

du matériel car cela risquerait de poser certains dangers.

Sicherheitsanleitungen • Deutsch

Dieses Symbol soll dem Benutzer in der im Lieferumfang enthaltenen
Dokumentation besonders wichtige Hinweise zur Bedienung und Wartung
(Instandhaltung) geben.

Dieses Symbol soll den Benutzer darauf aufmerksam machen, daß im Inneren
des Gehäuses dieses Produktes gefährliche Spannungen, die nicht isoliert sind
und die einen elektrischen Schock verursachen können, herrschen.

Achtung

Lesen der Anleitungen • Bevor Sie das Gerät zum ersten Mal verwenden, sollten Sie alle Sicherheits-und

Bedienungsanleitungen genau durchlesen und verstehen.

Aufbewahren der Anleitungen • Die Hinweise zur elektrischen Sicherheit des Produktes sollten Sie

aufbewahren, damit Sie im Bedarfsfall darauf zurückgreifen können.

Befolgen der Warnhinweise • Befolgen Sie alle Warnhinweise und Anleitungen auf dem Gerät oder in der

Benutzerdokumentation.

Keine Zusatzgeräte • Verwenden Sie keine Werkzeuge oder Zusatzgeräte, die nicht ausdrücklich vom Hersteller

empfohlen wurden, da diese eine Gefahrenquelle darstellen können.

Avertissement

Alimentations • Ne faire fonctionner ce matériel qu’avec la source d’alimentation indiquée sur l’appareil. Ce

matériel doit être utilisé avec une alimentation principale comportant un fil de terre (neutre). Le troisième
contact (de mise à la terre) constitue un dispositif de sécurité : n’essayez pas de la contourner ni de la
désactiver.

Déconnexion de l’alimentation• Pour mettre le matériel hors tension sans danger, déconnectez tous les cordons

d’alimentation de l’arrière de l’appareil ou du module d’alimentation de bureau (s’il est amovible) ou encore de
la prise secteur.

Protection du cordon d’alimentation • Acheminer les cordons d’alimentation de manière à ce que personne ne

risque de marcher dessus et à ce qu’ils ne soient pas écrasés ou pincés par des objets.

Réparation-maintenance • Faire exécuter toutes les interventions de réparation-maintenance par un technicien

qualifié. Aucun des éléments internes ne peut être réparé par l’utilisateur. Afin d’éviter tout danger
d’électrocution, l’utilisateur ne doit pas essayer de procéder lui-même à ces opérations car l’ouverture ou le
retrait des couvercles risquent de l’exposer à de hautes tensions et autres dangers.

Fentes et orifices • Si le boîtier de l’appareil comporte des fentes ou des orifices, ceux-ci servent à empêcher les

composants internes sensibles de surchauffer. Ces ouvertures ne doivent jamais être bloquées par des objets.

Lithium Batterie • Il a danger d’explosion s’il y a remplacment incorrect de la batterie. Remplacer uniquement

avec une batterie du meme type ou d’un type equivalent recommande par le constructeur. Mettre au reut les
batteries usagees conformement aux instructions du fabricant.

Vorsicht

Stromquellen • Dieses Gerät sollte nur über die auf dem Produkt angegebene Stromquelle betrieben werden.

Dieses Gerät wurde für eine Verwendung mit einer Hauptstromleitung mit einem geerdeten (neutralen) Leiter
konzipiert. Der dritte Kontakt ist für einen Erdanschluß, und stellt eine Sicherheitsfunktion dar. Diese sollte nicht
umgangen oder außer Betrieb gesetzt werden.

Stromunterbrechung • Um das Gerät auf sichere Weise vom Netz zu trennen, sollten Sie alle Netzkabel aus der

Rückseite des Gerätes, aus der externen Stomversorgung (falls dies möglich ist) oder aus der Wandsteckdose

ziehen.

Schutz des Netzkabels • Netzkabel sollten stets so verlegt werden, daß sie nicht im Weg liegen und niemand

darauf treten kann oder Objekte darauf- oder unmittelbar dagegengestellt werden können.

Wartung • Alle Wartungsmaßnahmen sollten nur von qualiziertem Servicepersonal durchgeführt werden. Die

internen Komponenten des Gerätes sind wartungsfrei. Zur Vermeidung eines elektrischen Schocks versuchen
Sie in keinem Fall, dieses Gerät selbst öffnen, da beim Entfernen der Abdeckungen die Gefahr eines
elektrischen Schlags und/oder andere Gefahren bestehen.

Schlitze und Öffnungen • Wenn das Gerät Schlitze oder Löcher im Gehäuse aufweist, dienen diese zur

Vermeidung einer Überhitzung der empndlichen Teile im Inneren. Diese Öffnungen dürfen niemals von

anderen Objekten blockiert werden.

Litium-Batterie • Explosionsgefahr, falls die Batterie nicht richtig ersetzt wird. Ersetzen Sie verbrauchte Batterien nur

durch den gleichen oder einen vergleichbaren Batterietyp, der auch vom Hersteller empfohlen wird. Entsorgen
Sie verbrauchte Batterien bitte gemäß den Herstelleranweisungen.

Instrucciones de seguridad • Español

Este símbolo se utiliza para advertir al usuario sobre instrucciones
importantes de operación y mantenimiento (o cambio de partes) que se
desean destacar en el contenido de la documentación suministrada con los
equipos.

Este símbolo se utiliza para advertir al usuario sobre la presencia de
elementos con voltaje peligroso sin protección aislante, que puedan
encontrarse dentro de la caja o alojamiento del producto, y que puedan
representar riesgo de electrocución.

Precaucion

Leer las instrucciones • Leer y analizar todas las instrucciones de operación y seguridad, antes de usar el

equipo.

Conservar las instrucciones • Conservar las instrucciones de seguridad para futura consulta.
Obedecer las advertencias • Todas las advertencias e instrucciones marcadas en el equipo o en la

documentación del usuario, deben ser obedecidas.

Evitar el uso de accesorios • No usar herramientas o accesorios que no sean especificamente recomendados

por el fabricante, ya que podrian implicar riesgos.

安全须知 • 中文

这个符号提示用户该设备用户手册中有重要的操作和维护说明。

这个符号警告用户该设备机壳内有暴露的危险电压，有触电危险。

注意

阅读说明书 • 用户使 用该设备前必须阅读并理 解所有安全和 使用说明。
保存说明书 • 用 户应保存安全说明书以备将来使用。
遵守警告 • 用户应遵守产品和用户指南上的所有安 全和操作说明。
避免追加 • 不要使 用该产品厂商没有推荐的工具或追加设备，以避免危险。

Advertencia

Alimentación eléctrica • Este equipo debe conectarse únicamente a la fuente/tipo de alimentación eléctrica

indicada en el mismo. La alimentación eléctrica de este equipo debe provenir de un sistema de distribución
general con conductor neutro a tierra. La tercera pata (puesta a tierra) es una medida de seguridad, no
puentearia ni eliminaria.

Desconexión de alimentación eléctrica • Para desconectar con seguridad la acometida de alimentación eléctrica

al equipo, desenchufar todos los cables de alimentación en el panel trasero del equipo, o desenchufar el
módulo de alimentación (si fuera independiente), o desenchufar el cable del receptáculo de la pared.

Protección del cables de alimentación • Los cables de alimentación eléctrica se deben instalar en lugares donde

no sean pisados ni apretados por objetos que se puedan apoyar sobre ellos.

Reparaciones/mantenimiento • Solicitar siempre los servicios técnicos de personal calicado. En el interior no

hay partes a las que el usuario deba acceder. Para evitar riesgo de electrocución, no intentar personalmente la
reparación/mantenimiento de este equipo, ya que al abrir o extraer las tapas puede quedar expuesto a voltajes
peligrosos u otros riesgos.

Ranuras y aberturas • Si el equipo posee ranuras o orificios en su caja/alojamiento, es para evitar el

sobrecalientamiento de componentes internos sensibles. Estas aberturas nunca se deben obstruir con otros

objetos.

Batería de litio • Existe riesgo de explosión si esta batería se coloca en la posición incorrecta. Cambiar esta batería

únicamente con el mismo tipo (o su equivalente) recomendado por el fabricante. Desachar las baterías usadas

siguiendo las instrucciones del fabricante.

警告

电源 • 该设备只能使用产品上标明的电源。 设备必须使用有地线的供电系统供电。 第三条线（

地线）是安全设施，不能不用或跳过 。

拔掉电源 • 为安全 地从设备拔掉电源，请拔掉所有设备后或桌面电源的电源线，或任何接到市电

系统的电源 线。

电源线保护 • 妥善布线， 避免被踩踏，或重物挤压。
维护 • 所有维修必须由认证的维修人员进行。 设备内部没有用户可以更换的零件。为避免出现触

电危险不 要自己试图打开设备盖子维修 该设备。

通风孔 • 有些设备机壳上有通风槽或孔，它们是用来防止机内敏感元件过 热。 不要用任何 东西

挡住通风孔。

锂电池 • 不正确的更换电池会有爆炸的危险。必须使 用与厂家推荐的相同或相近型号的电池。按

照生产厂的建议处理废弃电 池。

FCC Class A Notice

This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to part 15 of the FCC rules. The Class A limits provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio frequency energy and,
if not installed and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a residential area is
likely to cause interference; the user must correct the interference at his own expense.

NOTE: This unit was tested with shielded I/O cables on the peripheral devices. Shielded

cables must be used to ensure compliance with FCC emissions limits.

For more information on safety guidelines, regulatory compliances,

EMI/EMF compatibility, accessibility, and related topics, see the “Extron Safety

and Regulatory Compliance Guide” on the Extron website.

Conventions Used in this Guide

Notications

ATTENTION: Attention indicates a situation that may damage or destroy the product

or associated equipment.

NOTE: A note draws attention to important information.

TIP: A tip provides a suggestion to make working with the application easier.

Software Commands

Commands are written in the fonts shown here:

^AR Merge Scene,,Op1 scene 1,1 ^B 51 ^W^C

[01] R 0004 00300 00400 00800 00600 [02] 35 [17] [03]

E X! *X1&* X2)* X2#* X2! CE}

NOTE: For commands and examples of computer or device responses mentioned

in this guide, the character “0” is used for the number zero and “O”
represents the capital letter “o.”

Computer responses and directory paths that do not have variables are written in the
font shown here:

Reply from 208.132.180.48: bytes=32 times=2ms TTL=32

C:\Program Files\Extron

Variables are written in slanted form as shown here:

ping xxx.xxx.xxx.xxx —t

SOH R Data STX Command ETB ETX

Selectable items, such as menu names, menu options, buttons, tabs, and field names are
written in the font shown here:

From the
Click the OK button.

File menu, select New.

Copyright

© 2012 Extron Electronics. All rights reserved.

Trademarks

All trademarks mentioned in this guide are the properties of their respective owners

Contents

Introduction............................................................ 1

MLA VC10 Plus Description................................. 1

MLA VC10 Plus Features ..................................... 1

Panels and Connections ....................................... 3

Front Panel Connections and Features ................. 3

Rear Panel Connections ...................................... 4

Installation

and Cabling ............................................................ 5

Installation Overview ........................................... 5

Connections for Volume Control ......................... 6

Volume Control by Potentiometer ................... 6

Volume Control by Variable DC Voltage .......... 8

Connections to a Power Supply......................... 11

RS-232 Connections ......................................... 13

Connections to an

Extron Control Processor .............................. 13

Connections to a

Third-party Control System ........................... 14

Relay................................................................. 15

Mute Control ................................................ 15

Other Uses .................................................... 15

Software Control ................................................. 16

Computer Requirements ................................... 16

About the Software .......................................... 16

Activating the USB Port for the First Time ...... 17

Using DataViewer ......................................... 17

Conguring the Extron Controller ................. 18

Software Installation ..................................... 18

About the Firmware .......................................... 18

Downloading the Firmware ........................... 18

Installing the Firmware .................................. 19

Resetting to the Factory Installed Firmware ... 19

Operation .............................................................. 20

Operation ......................................................... 20

Voltage or Resistance Control........................ 20

Inverse Mode ................................................ 21

Linear or Logarithmic Taper Mode ................. 22

Auto Mute .................................................... 22

Soft Start ...................................................... 22

Troubleshooting ............................................... 22

Specifications ....................................................... 25

Parts and Accessories ......................................... 27

Included Parts ................................................... 27

Optional Accessories ......................................... 27

Reference Material ............................................. 28

Control Resistance and Voltage for

Common Amplifiers ......................................... 28

SIS Commands ..................................................... 31

Introduction to SIS ........................................... 31

Symbols Used in this Guide ............................... 32

Error Messages ................................................. 33

Command and Response Table for

SIS Commands ................................................ 33

Mounting .............................................................. 37

Tabletop Placement ........................................... 37

Rack Mounting ................................................. 37

UL Guidelines for Rack Mounting .................. 37

Rack Mounting Procedure ............................. 38

Under-desk Mounting ....................................... 38

Through-desk Mounting ................................... 38

MLA VC10 Plus • Contents v

MLA VC10 Plus • Contents vi

Introduction

This user guide contains information about the Extron MLA VC10 Plus volume control

module with instructions for experienced installers on how to install, configure, and
operate the equipment.

Unless otherwise specied, references in this guide to the “MLA” relate to the features or
operation of the MLA VC10 Plus.

References to the “control processor” or “controller” refer to the Extron or third-party
controller that provides RS-232 commands to the MLA VC10 Plus.

References to “amplier” relate to any amplier and mixer under the control of the MLA.

MLA VC10 Plus Description

The MLA VC10 Plus is a MediaLink® accessory volume control module. It converts RS-232
commands from a control system into voltage or impedance changes to control audio

ampliers with volume and mute control ports. It can be used with Extron or third-party

controllers and audio amplifiers that have remote volume control capability.

The MLA VC10 Plus is compatible with the following control devices:

z Extron MediaLink controllers
z Extron IP Link

z Third party control systems capable of RS-232 serial control

®

control processors

The MLA VC10 Plus is compatible with Extron ampliers, including:

z MPA 152 and MPA 401

z XPA 1002 and XPA 2001

z MP 101

MLA VC10 Plus Features

Volume and mute control — The MLA VC10 provides volume and mute control for the
Extron MPA or XPA half-rack series ampliers and many third-party ampliers.

High resolution volume control range — Provides smooth volume changes without
audible level jumps.

Compatible with multiple control systems — The volume control module uses an

RS-232 protocol that is compatible with Extron and third-party serial-capable controllers.

Adjustable maximum limit on variable voltage or resistance control — The

amplier volume level is adjusted using voltage (0 - 10 VDC) or resistance (0 - 10 kilohm

potentiometer) control. The maximum control voltage or resistance range can be reduced
to avoid damage to third party amplifiers that need a lower control range or to limit the
maximum audio output of the amplifier.

Linear or logarithmic taper modes — These modes are available for both voltage and
resistance control and provide a choice between consistent linear or natural logarithmic
volume changes.

MLA VC10 Plus • Introduction 1

Inverse mode — In normal mode, 0 is mute and 10 VDC or 10 kilohm is the maximum

volume. In inverse mode, this reverses the output to 0 (maximum volume) to 10 VDC or

10 kilohm (minimum volume).

Relay switch — This switch has a Normally Open (NO) pin and a Normally Closed (NC)
pin. This relay can be used to mute audio on an amplifier or mixer.

Auto Mute — When the volume level is at 0, this feature allows the MLA VC10 Plus to

trigger this relay to mute the amplifier, via mute contact closure terminals on the amplifier.

By default this feature is enabled.

Soft Start — The audio level is gently ramped to restore volume to its previous level after
a mute or a power cycle to prevent loud bursts of sound and to protect the amplifier and
speakers from possible damage.

Isolation — Isolated digital circuitry prevents noise in the signal path. All control ports are
isolated from each other to eliminate induced noise.

RS-232 serial control — The MLA VC10 Plus can be controlled by Extron Simple

Instruction Set (SIS™) commands either via the controller or directly from a PC using the

front panel USB port or the rear panel 3-pole captive screw connector.

Optional ENERGY STAR® qualified power supply — This external universal power
supply (PS 1210 C, part number 70-775-01) provides worldwide compatibility, low power
consumption, and reduced operating costs.

RELAY

Extron

CONTROL

OUTPUT

REMOTE

RS-232

POWER
12V

0.3A MAX

Tx Rx G G GV C

1

VCR

CONFIG

MLC 104 IP PLUS

2

DVD

3

PC

4

DISPLAY

Extron
MLC 104 IP Plus

MediaLink
Controller

ON

VOLUME

OFF

RS-232

1 2

LIMITER/PROTECT

SIGNAL
OVER
TEMP

MLA VC10 Plus

NO NCC

R

Volume Control Module

V-DC

Variable
Impedance
Output

XPA 1002

Extron
SI 26

Surface-mount
Speakers

Figure 1. MLA VC10 Plus Application Diagram

Extron
XPA 1002

Power
Amplier

MLA VC10 Plus • Introduction 2

Panels and

Connections

This section describes the features and connectors for the MLA VC10 Plus:

z Front Panel Connections and Features

z Rear Panel Connections

Front Panel Connections and Features

MLA VC10 Plus

a

b

MUTE

RELAY

CONFIG

R

e

d

c

Figure 2. MLA VC10 Plus Front Panel

a Power and Activity LED —

z Is off when the unit is not receiving power

z Lights solid green when the unit is receiving power

z Continuously flashes green while SIS commands are received.

b Audio Mute LED — lights solid green when volume level is at 0 or is muted.
c Relay LED —

z Lights solid green when the relay is triggered or toggled on.

z Pulses when the relay is momentarily triggered

d Config port — A USB cable can be connected to this mini B USB female port when

using a PC to connect to the MLA VC10 Plus.

NOTE: During configuration, the host PC provides power through the USB cable.

This is sufficient to power the unit during configuration only. For normal

use, the unit must receive power from a 12 VDC power supply.

e Reset Button — used to reset to the factory-installed firmware (see page 19).

MLA VC10 Plus • Panels and Connections 3

Rear Panel Connections

fg jih

CONTROL

OUTPUT

POWER

REMOTE

12V

0.3A MAX

RS-232

Tx Rx GG GVC

V-DC

RELAY

NO NCC

R

Figure 3. MLA VC10 Plus Rear Panel

f Power — Connect a 12 VDC power supply to this two pole captive screw connector.

The MLA VC10 Plus can be wired to share the power supply with other products
(see “Sharing a Power Supply with an Extron Controller” page 12 for more
information). The Extron power supply (part number 70-775-01) is optional.

ATTENTION: Before connecting power, see “Connections to a Power Supply”

on page 11 for important information about using the power
supply.

g RS-232 control — The MLA VC10 Plus is controlled by RS-232 instructions from

a MediaLink, IP Link, or third-party controller or a PC. Connect the RS-232 control
cables, from the controller or PC to this 3.5 mm, 3-pole captive screw connector.

h V-DC control — To use variable DC voltage output to control the volume of an

amplier, connect the MLA VC10 Plus to the amplier using this 3.5 mm, 2-pole

captive screw connector.

NOTES: The amplifier audio level can be controlled by either voltage or by

resistance but, at any time, only one can be active, see “Modes” in the
SIS commands on page 35.

i Resistance Control (default setting) — To use the digital potentiometer to control

an amplier, connect the MLA VC10 Plus to the amplier using this 3.5 mm, 3-pole

captive screw connector.

j Relay Switch — To use the relay for mute control or other purposes, determine

whether the amplifier needs a Normally Closed (NC) or Normally Open (NO) relay.
Connect the common (C) pole and either the NO or the NC pole of the captive screw
connector to the amplifier.

MLA VC10 Plus • Panels and Connections 4

Installation and Cabling

This section describes

z Installation Overview

z Connections for Volume Control

z Connections to a Power Supply

z RS-232 Connections

z Relay

Installation Overview

This section provides a brief overview of how to install and set up the MLA VC10 Plus.

1. Decide where the MLA VC10 Plus will be placed and, if necessary, any mounting

requirements (see page 37).

NOTE: To avoid picking up background noise in the cable, use shielded cable

(for example Extron STP 22 cable) and place the MLA VC10 Plus as close
as possible to the amplifier. Extron recommends that the maximum cable
length between the MLA VC10 Plus and the amplifier should be six feet.

2. Read the user guide for the amplifier or mixer. Determine the remote volume control

requirements of the unit.

Potentiometer mode (default) — connect the potentiometer terminals on the
MLA VC10 Plus to the amplifier (see pages 6 and 7).

NOTE: The majority of amplifiers researched and tested by Extron work with the

MLA VC10 Plus straight from the box, using 10 kilohm resistance control,

without further configuration.

Voltage mode — The unit needs configuration, using SIS commands. Determine the
control voltage of the amplifier (see ”Volume Control by Variable DC Voltage,” on
page 8) and connect the voltage terminals on the MLA VC10 Plus to the amplifier
(see page 9).

If necessary, connect a PC to the front panel USB port and configure the
MLA VC10 Plus using SIS commands.

3. After conguring the unit, disconnect the front panel USB connection.

4. Connect the three RS-232 terminals of the MLA VC10 Plus to an Extron control

processor (see page 13) or a third party control device (see page 14).

5. To use the relay control, connect the relay terminals of the MLA VC10 Plus to the

amplifier (see page 15).

MLA VC10 Plus • Installation and Cabling 5

6. Connect a power supply (see page 11).

Extron

ATTENTION: Read the attention points on page 11 before connecting the

power supply.

If the MLA VC10 Plus is being used with Extron MLC or IP Link control processors, the

units can share a power supply (see the wiring diagram shown on page 12). If the
volume control module is used with any other control device, it requires a separate

12 VDC power supply. Extron provides a 12 VDC, 1 A power supply (part number

70-775-01), which must be purchased separately.

Connections for Volume Control

The MLA VC10 Plus controls the remote volume control port of an amplier. All Extron

MPA and half-rack XPA amplifiers and most third-party models can be controlled by a

potentiometer, which is the default setting for the MLA VC10 Plus. Other third-party

amplifiers may require a variable DC voltage signal to control the audio volume.

Consult the user guide for the amplifier to find out the specific requirements of your

equipment before connecting it to the MLA VC10 Plus. Additionally, the audio can be

muted by connecting the captive screw relay connections to the contact closure mute
terminals of the amplifier, if they are available.

Volume Control by Potentiometer

The following examples show how to wire the resistance control terminals of the

MLA VC10 Plus to the Extron MPA and half-rack XPA ampliers, or some common

third-party amplifiers.

When using three-pin potentiometer control, RS-232 commands control the variable
resistance across the signal (wiper) pin (C) to the ground pin (G). Across the reference (V)
and ground (G) will always be xed at 10 kilohm. Other controllers and ampliers not

shown here require similar connections, but you must read the appropriate user guides to
ensure the wiring is correct.

Extron Amplier

This example shows how to connect the MLA VC10 Plus to an Extron amplier. All Extron

amplifiers can be controlled by a potentiometer, using three pins.

NOTES: • By default, the MLA VC10 Plus control mode is set to potentiomenter and

the maximum resistance output range is set to 10 kilohm. These are the

settings required by all Extron amplifiers.

• Volume control pins may be labeled as V, C, and G (see the half-rack

XPA Series Amplifier) or 10V, Vol/Mute, and G (see the MPA Amplifier). The

wiring and function are the same, whichever way your product is labeled.

1. If necessary, use SIS commands to set

the control mode (see page 35) to
potentiometer and set the maximum

potentiometer output range (see

page 35).

Extron

MLA VC10 Plus

R

GVC

Extron MPA

Amplifier

10V 50mA

VOL/MUTE

REMOTE

OR

Half-rack

XPA Series

Amplifier

10V 50mA

GVC

G

STANDBY

2. Connect the reference voltage pin (V) from

the MLA VC10 Plus to the reference voltage
terminal (10V on the MPA; V on the XPA).

Ground

G

Control (variable)

C

Reference

V

MLA VC10 Plus • Installation and Cabling 6

G
C
V

3. Connect the ground pin (G) from the MLA VC10 Plus to the ground terminal ( on the

MPA; G on the XPA).

4. Connect the signal (wiper) pin (C) from the MLA VC10 Plus to the signal terminal

(VOL/MUTE on the MPA; C on the XPA).

Third-party amplier (three terminals)

ATTENTION: For third-party amplifiers, consult the user guide for the amplifier to see

how the manufacturer has labeled the different connectors and whether
two or three terminals are used for potentiometer control.

This example shows the MLA VC10 Plus connected
to an Ashly NE series amplier, which requires

a maximum potentiometer output range of
10 kilohms.

Extron MLA VC10 Plus

R

GVC

Ashly NE series

CH 4

CH 3

CH 2

GND

+5V

CH 1

1. Connect the reference voltage pin (V) from

the MLA VC10 Plus to the reference voltage
terminal (+5V) on the amplier.

2. Connect the ground wire (G) from the

MLA VC10 Plus to the ground terminal ( ) on
the amplifier.

G

Ground

Control (variable)

C

Reference

V

3. Connect the signal (wiper) wire (C) from the

MLA VC10 Plus to the signal terminal (CH 1)

on the amplifier.

Third-party amplier (two terminals)

This example shows the MLA VC10 Plus connected

to a TOA 900 Series amplifier, which requires a
potentiometer output range of 10 kilohms.

1. Connect the ground wire (G) from the

MLA VC10 Plus to the left REMT VOL terminal on

the amplifier.

2. Connect both the reference wire (V) and the signal

wire (C) from the MLA VC10 Plus to the right
REMT VOL terminal on the amplier.

This can be achieved by connecting the signal

terminal (C) of the MLA VC10 Plus to both the
right REMT VOL terminal on the amplifier and the
reference terminal (V) of the MLA VC10 Plus.

Extron MLA VC10 Plus

R

TOA 900 Series

GVC

G Ground

Connect the signal (C) and reference (V)
terminals of the MLA VC10 Plus.
Connect the signal (C) terminal to the amplifier.

C Control (variable)

Amplifier

MUTE

GND

2

MUTE

REMT

VOL

1

MLA VC10 Plus • Installation and Cabling 7

Volume Control by Variable DC Voltage

When volume is being controlled by variable voltage, serial SIS commands sent from the
controller to the MLA VC10 Plus control the voltage output across the signal (+) and
ground (G) pins. This in turn, controls the audio level of the amplier.

Consult the user guide for the amplifier to find out the specific requirements of your

equipment before connecting it to the MLA VC10 Plus. If the amplier requires variable

DC voltage control, you will need to find out the maximum control voltage, to avoid
damaging the equipment. The user guide for the amplifier may list the required voltage.
The table that starts on page 28 shows the voltage requirements of many common

ampliers. However, Extron recommends that you conrm the voltage yourself by reading

the user guide for the amplifier or, if necessary, using a voltmeter.

This section describes how to measure the control voltage for two widely -used amplifiers.

z Peavey UMA 35T II

z Biamp Precedence CMA 60

NOTE: The MLA VC10 Plus is compatible with a wide range of amplifiers. The models

shown in this section are included as examples only. The MLA VC10 Plus is not

limited to working with only the amplifiers shown in this guide.

After describing how to measure the control voltage, the guide describes how to connect
the MLA VC10 Plus to an amplier for volume control by voltage.

Measuring the Peavey UMA 35T II control voltage

In the example shown below, the voltage control pins are labeled “Remote Vol.” Use a
voltmeter, set to VDC, to measure the voltage. Make a record of the measured voltage and

which terminal is ground. If the voltage is negative the meter probes need to be reversed.

Figure 4. Measuring the Peavey UMA 35T II Control Voltage

MLA VC10 Plus • Installation and Cabling 8