LA Audio MS1224 User Manual

Active Mic

Splitter

Operation Manual

August ‘04

This page has been left intentionally blank for your notes

Page 2

CONTENTS

1.0 OVERVIEW 4

2.0 TECHNICAL SPECIFICATION 5

3.0 INSTALLATION 6-7

3.1 Inspection and unpacking

3.2 Operating Environment

3.3 CE Standard and LVD

3.4 Power Requirement

3.5 Warranty

4.0 DESCRIPTION OF CONTROLS 8

4.1 Phantom

4.2 +48V indicator

4.3 Pad

4.4 Listen

5.0 EXTERNAL CONNECTIONS 9-14

5.1 Input

5.2 Link

5.3 Output A, B, C and D

5.4 Power In

5.5 Power Out

5.6 Signal Levels

5.7 Multiway Connector Option

5.8 Input-Output Options

5.9 Grounding Output D

6.0 POWER SUPPLY UNIT 15-17

6.1 Description of Front Panel

6.2 External Connections

6.3 Power Requirements

7.0 DIMENSIONS 18

Page 3

1.0 OVERVIEW

PRODUCT OVERVIEW

Main Features:

• 12 Channel 1 into 4 (12 into 48) Active Mic Splitter

• Unique Input & Output configuration options

• Unity Gain signal path for ease of set-up

• Drives long cable runs without level loss

• Compact design e.g. a 48 channel System in 13U (including Power Supply)

• Channel Monitoring facility

• Individual Input and Output group earth lift switches

The MS1224 is a 12 channel, 1 into 4 Unity Gain Active Microphone Splitter designed f or
applications where multiple feeds are r equired from one set of microphones without the
signal degradation experienced with passive splitting solutions. The Unity Gain design
principle combined with excellent line driving ability ensures that unity levels are delivered
at the end of each feed, even over considerable distance, thereby saving time in
recalibrating levels.

Each of the MS1224's channels has four independently buffered, transformer balanced
outputs and a fif th dedicated parallel Link output. The Link output may be used to provide
a direct, non active feed, for instanc e to the FOH cons ole, or it can be used to daisy chain
adjacent channels to provide more output feeds from a s ingle microphone, for instance
for Press Box applications . The inputs are electronically balanced with a Pad switch for
connection of line level signals. Switchable Phantom Power is provided with a Phantom
Presence LED.

The MS1224 incorporates a channel monitoring circuit, which is accessed on the PSU
unit. Each channel has a Listen button that connects it momentarily both to an LED
bargraph and headphone socket on the PSU fr ont panel. The headphone monitor circuit
incorporates a dynamics enhancem ent and protection s ystem. T his c ontrols the dynamics
of the signal in a way that amplifies very low background levels whilst limiting high signal
levels. This enables m onitoring of microphone f unction during set up without the need of
a vocalist being present on the mic. It also provides user protec tion against sudden loud
signals.

A unique design feature of the MS1224 is the option to conf igure the way that Input and
Output connectors are pres ented on the front and rear of the unit. As each custom er has
their own views on this we have given the flexibility of presenting the Input and two
Outputs on the front and three Outputs on the rear , or vice-versa. In addition the Output
designated as Link can be positioned either below the Input connector, or above the
group of three Outputs. Thereby giving four possible permutations. The required
configuration can be specified ex-works or simply reconfigured at a later stage.

Each XLR connector on each c hannel is equipped with 3 pin molex c onnectors for wiring
to a multicore set. A standar d rear panel multicore plate is available for use with 56 way
EDAC connectors. Thereby all connectors per c hannel can be accessed via a multicore
cable.

Page 4

2.1 MS1224 ACTIVE MIC SPLITTER

ELECTRICAL
Frequency Response: 20Hz to 20kHz, +0, -0.5dB

Equivalent Input Noise: -122dBu, 20Hz to 20kHz
THD + Noise: < 0.01%

Input Impedance: 2k
Maximum Input Level: 0dBu (+20dBU with Pad)

Output Impedance: < 15R
Load Impedance: > 150R
Gain: 0dB (-20dB with Pad)

Bargraph Calibration: -60dB to +20dB
Power Requirement: +17V, -17V DC and +48V

PHYSICAL
Input Connector: XLR 3 pin female (Pin 2 = hot)

Output Connector: XLR 3 pin male (pin 2 = hot)
Interconnection: 36 way Centronics cable
Multiway connector option: 56 pin EDAC

Dimensions mm (ins): 483 (19") W
225 (8.85") D
133 (5.25") H (3U)

Weight: Unit 5.5kg (12.1lbs)
Shipping 6.1kg (13.4lbs)

Temperature Range: Operating 0°C to 50°C
Storage -30°C to +75°C

2.2 MS1224 POWER SUPPLY

Power connector: Detachable lead IEC
Dimensions: 483 (19") W

225 (8.85") D
44 (1.75") H (1U)

Weight: Unit 3.5kg (7.7lbs)
Shipping 4.1kg (9.02lbs)

Power requirement: 85VA, 115/230V AC, 50/60Hz

2.0 TECHNICAL SPECIFICATIONS

Page 5

3.0 INSTALLATION

3.1 INSPECTION AND UNPACKING

The MS1224 Active Mic Splitter and Power Supply units have been carefully
packed at our fac tory in a carton designed to withstand handling in trans it. Should
the unit appear to have been dam aged in transit, notify your dealer immediately
and do not discard any of the packing. The carton should contain -

• The MS1224 Active Mic Splitter or MS1224 Power Supply unit

• Power cord

• 36 way Centronics cable (not with the Power Supply)

• Operator Manual (this book)

3.2 OPERATING ENVIRONMENT

The MS1224 Active Mic Splitter and Power Supply units are designed to operate
between 0°C and 40°C (32-112°F) with relative humidity no more than 80%.
Should the units be installed in an equipment rack, ensure that the ambient
temperature conforms to these levels.

3.3 CE STANDARDS AND THE LOW VOLTAGE DIRECTIVE (LVD)

The MS1224 Active Mic Splitter and Power Supply units have been designed to
comply with the latest Electromagnetic Com patibility (EMC) regulations. However
we recommend you do not operate the unit close to strong emitters of
electromagnetic radiation suc h as power trans form er s, m otors, m obile telephones
or radio transmitters.

The unit should only be connec ted to a power supply of the type described in 3.4
POWER REQUIREMENTS or as marked on the unit. Disconnect the mains
supply before removing any cover.

See Section 6.3, concerning power requirements for the MS1224 Power Supply.

3.4 POWER REQUIREMENTS

The MS1224 Active Mic Splitter is designed to work from low voltage DC supplies
only. The MS1224 Power Supply provides Phantom power (+48V) and Audio
supplies of +17V and -17V - see Section 6.0.

3.5 WARRANTY

Your LA Audio MS1224 Active Mic Splitter and Power Supply units have been
manufactured to a high standar d using quality components. If correctly installed
and operated the unit should give years of problem free operation.

However in the event of a def ec t in material or workmanship causing f ailur e of the
unit within 1 year of the date of original purchase we will agree to repair, or at our

Page 6