BSS Audio MSR-602 Series User manual

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Welcome to the MSR-602/604 II Users Manual
Welcome
This manual is provided to assist sound engineers, installers and
consultants to fully understand the MSR-604 II and to benefit from its
full capability.
As opposed to most manuals, the contents can be read like a book.
At the same time, the information is structured under a series of broad
headings for easy access. So where possible within each section:
· The most immediate information appears at the head of each section
under the main title.
· As you read further into each subsequent section, more detailed,
specificinformationisgiven.
Should you have any comments or questions about applying the
MSR-604 II within your application, please write to us at the address in
thewarrantysection.
V1.4 29 April 1996
This Manual is the COPYRIGHT of BSS Audio. All reproduction and copying, other than for the legal
owner's personal use, or disclosure of part or whole to a third party, without prior written authorisa-
tion, is in violation of the European Copyright Convention. BSS Audio 1996
MSR-600 II Series
User's Manual

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MSR-600 II Series
This equipment has been tested and found to comply with the
following European Standards for Electromagnetic Compatibility.
Emission Specification EN55013 1990 Class B (Associated equipment)
Immunity SpecificationEN50082/1 1992 (RF Immunity, Fast
Transients and ESD)
Mains Disturbance EN61000/3/21995
For continued compliance ensure that all input and output cables are
wired with cable screen connected to pin 1 of the XLR. The input XLR pin
1 on BSS equipment is generally connected to chassis via a capacitor to
prevent ground loops whilst ensuring good emc compatibility.

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Table Of Contents
Table Of Contents
1.0 Introduction 4
1.1 MSR-604 II Mic/Line Signal Splitter 5
1.2 MSR-602 II Power Supply Unit 6
2.0 Unpacking 7
2.1 Warranty 7
2.2 Warning 7
3.0 Connections and Control Descriptions 8
3.1 AC power connections and control settings 9
3.2 DC power connections 11
3.3 Audioconnections 12
3.4 MSR-602 II Controls 13
3.5 MSR-604 II Controls 14
4.0 System Implementation and Use 16
4.1 Racking 16
4.2 Grounding 18
4.3 Channel coding 19
4.4 Dualpowersupplyoperation 20
4.5 Output drive level setting 20
4.6 Multiple output Distribution Amplifier
configuration 22
4.7 Stereo Summing Configuration 24
5.0 Compatibility With Pre Mk II Systems 25
5.1 Installing MSR-604 IIs in a Mk 1 system 25
5.2 Installing pre Mk II MSR-604s into a new system 26
5.3 Installing a Mk II power supply into a Mk I SYSTEM
and vice versa 26
6.0 Appendix A 27
6.1 System block diagram and circuit description 27
6.2 TransientSuppressorreplacement 28
7.0 Appendix B 29
7.1 Inputtransformerbalancing 29
7.2 Outputtransformerbalancing 29
8.0 Technical Specifications 30
9.0 Warranty 33

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MSR-600 II Series
1.0 Introduction
Introduction
It is not uncommon within a sound system which uses microphones as
a source of programme, for that microphone to be connected to the
input of a number of different processing facilities.
An example of this would be in sound reinforcement work where a
stage microphone is required to drive the main ‘front of house’ mixing
console,the stage monitoringmixing console,a mobile recordingstudio
andquitepossibly an outsidebroadcastrecording vehicle.
It is also common within such a system for the microphone to be
connectedto considerable lengthsofshielded cable beforebeing
terminatedattheprocessing facilitys input connector.
Such a load on the microphone is very much in excess of its design
capability, and as a consequence the level and quality of the sound is
impaired.(Fig. 1)
A further complication can arise within such a system from multiple
earthing as each of the processing facilities would be providing its own
ground.
To overcome these problems it is quite common for a multiple winding
transformerto beused which providesseparate secondary windings for
each of the required outputs. This solution will solve the multiple
grounding problems, however it does not tackle the sound level and
quality problem as, being a passive device, it has no power amplification
capability.
Costeffective activeelectronic solutions provedelusive until the
introduction of the original BSS MSR-604 overcame the problems of
noise and headroom. The current MSR-604 II further improves upon the
performance of the original unit with yet greater dynamic range,
Fig. 1 Microphone
Loading

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MSR-604 II Microphone Signal Splitter
flexibility of gain and level control, internal bus routing, signal meter-
ing and a headphone monitoring facility.
The MSR-604 II is a four channel, four way signal splitting package
and the MSR-602 II is the system power supply capable of supplying
power for 40 channels, that is, 10 separate MSR-604 II units.
The MSR-604 II has four channels, each of which may be isolated and
usedtotally independently from the nextor, by internalre-configuration,
be interconnected to form distribution amplifier sections with a single
input driving up to 64 outputs.
The low noise floor requirement necessitates a remote power supply
system, the MSR-602 II, which provides the required DC voltages.
A MIC/LINE switch introduces a 20dB input pad, which in combination
with the 5 step GAIN switch allows any input signal below + 33dBu to
be perfectly matched to the MSR-604 II’s dynamic range. The setting up
process is further assisted by the provision of a momentary LISTEN
switch which routes the signal to a calibrated HEADROOM meter and a
headphonemonitor amplifierbuilt into the MSR-602 II power supply
unit. Each channel also has a CLIP LED to give constant warning against
signal overdrive. As a further refinement a separate 10dB input pad may
be activated from the front of house mixing console by switching the
desks phantom supply. This remote attenuator allows the engineer to
preserve the channel headroom directly from the consolein the event
that an input is overdriven.
Eachchannel also providesa separate phantompowering selector switch
providingan independent 48Vacross the ‘micinput’connector.
Each channel has two low impedance electronically balanced outputs
on the rear panel to feed the MAIN (Front of House) and the MONITOR
mixingconsoles. These outputsmay be independentlyconfigured by
internal header blocks to drive at mic (+3dBu clip) or at line (+23dBu
clip) levels. A third setting allows these outputs to be driven at +13dBu
clipwhich gives again/headroom structure compatiblewith earlier
versions of the MSR-604. The two FEED XLR connectors on the front
panel offer microphone level transformer isolated and balanced
outputs.
1.1 MSR-604
Mic/Line Signal
Splitter

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MSR-600 II Series
MSR-602 II Power Supply
The MSR-602 II is the system power supply providing all the neces-
sary DC voltages for the MSR-604 II. It utilises a custom designed low
field toroidal transformer and separate mumetal screen to reduce the
possibility of mains field coupling into the electronic circuitry of the
MSR-604II.
TheHEADROOM LEDmeter and high quality headphone amplifier give
theoperator absoluteconfidence insignal integrity during setting up,
and provide an indispensable aid to trouble shooting and fault detection.
The signal wiring involved is contained with the power wiring in a
multicorecableforsimpleinterconnectionbetweenunits.
In addition it also carries the main system ground switch which has
important considerations within a large system for both safety and noise.
PLEASE READ SECTION 4.2 CAREFULLY PRIOR TO OPERATING
THE COMPLETE SYSTEM.
1.2 MSR-602 II
Power Supply

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2.0 Unpacking
Unpacking
Warranty
Warning
As part of our system of quality control, this product is carefully
inspectedbefore packingto ensureflawless appearance. After
unpacking the units, please inspect for any physical damage and retain
the shipping carton and all relevant packing materials, should the unit
requirerepacking.
In the event that damage has occurred, immediately notify your dealer,
so that a written claim to cover damages can be initiated.
The MSR-604 II and MSR-602 II units are warranted by BSS to the
originalpurchaser, against defects in workmanshipand materials usedin
manufacture, for a period of one year from date of shipment. Faults due
topurchasermisuse, unauthorised modifications oraccidentsarenot
coveredby this warranty.
No other warranty is expressed or implied.
If the unit is faulty, it should be sent, shipping prepaid, to an authorised
dealer of the manufacturer stating the faults found.
The serial number must be quoted in all correspondence relating to this
warranty.
Becausethisequipment is connectedbetweenthe microphone and
mixing console or patching system, it is important for safety and system
noise that a proper earthing system is implemented within the cabling
system.
CONSEQUENTLY SECTION 4.2 OF THIS MANUAL MUST BE READ
PRIOR TO INSTALLATION AND USE.
2.1 Warranty
2.2 Warning

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MSR-600 II Series
Connections and Control Descriptions
3.0 Connections and Control Descriptions
Fig. 2 MSR-602 II and
MSR-604 II

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AC Power Connections and Control Settings
Before connecting the MSR-602 II to the AC power source, check
that the voltage selector switch located on the rear panel is cor-
rectly set. If a change is necessary, ensure that the mains fuse is
also changed for one of the correct rating. Before connecting the
DC power leads, check that the system ground switch on the rear
panel is also correctly set to ‘earthed’.
The power cord attached to this unit carries the following informa-
tion label.
WARNING:THISAPPLIANCEMUSTBEEARTHED
IMPORTANT: The wires in this mains lead are colour coded in
accordancewiththefollowingcode.
Greenandyellow: Earth
Blue : Neutral
Brown : Live
As the colours of the wires in the mains lead of this appliance may
notcorrespond with the colouredmarkingsidentifying the terminals
in your plug, proceed as follows:
The wire which is coloured green-and-yellow must be connected to
the terminal in the plug which is marked with the letter ‘E’ or by the
earth symbol which is ‘ ‘, or coloured green or green-and-yellow.
The wire which is coloured blue must be connected to the terminal
which is marked with the letter ‘N’ or coloured black.
The wire which is coloured brown must be connected to the terminal
which marked with the letter ‘L’ or coloured red.
Those units that are supplied to the North American market will
have an integral moulded 3 pin connector which is provided to
satisfy required safety standards.
3.1 AC Power
Connections and
Control Settings
Fig. 3 MSR-602 II
Voltage Switch and
Mains Fuse

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MSR-600 II Series
Voltage Setting
Safety EarthingAC Power Fusing
The mains voltage selector switch provides simple, external adjust-
ment for operation on all international AC power standards.
At each switch position there is an acceptable tolerance over which
the performance of the unit will not be affected and this is 90v-130v
for the 120V position, and 180V-260V for the 240V position. If you
subject the unit to voltages in excess of this, you are likely to cause
damage. If the mains voltage is below those specified, there will be
reduced performance before the unit finally fails to work.
The green/yellow wire of mains cord must always be connected to the
electrical installations Safety Earth or Ground. It is essential for personal
safety, as well as proper operation of the unit, and is internally
connected to all exposed metal surfaces. Any rack framework that this
unit might be mounted into is assumed to be connected to the same
grounding circuit. the MSR-604 II has electronically balanced audio
connections and does not need disconnection of any safety earth for the
avoidanceofhum loops.
The incoming mains power is fused within the MSR-602 II by the fuse
holder mounted on the rear panel. If it needs to be replaced it must be
properly rated as: 20mm F5A for 240V voltage setting or F6.3A for 120V
voltage setting. It is most important for continued safety that this
specification is strictly adhered to, and you will have found that spare
fuses of this rating are supplied together with your unit and manual.
It is very unlikely that this fuse will fail during normal use, and must be
treated with some caution as to the cause, if it should do so. One of
the most likely reasons will be because the mains voltage switch on
the rear panel is incorrectly set. Another reason can be the inadvert-
Fig. 4 DC Connection
Cabling
3.11 Voltage
Setting
3.12 Safety
Earthing
3.13 AC Power
Fusing