NAD 911 User Manual

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• OWNER'S MANUAL

• MANUEL D'INSTALLATION

• BEDIENUNGSANLEITUNG

Warning: To reduce the risk of fire or electric shock,
do not expose this unit to rain or moisture.

The lightning flash with an arrowhead symbol within an equilateral trian-

gle, is intended to alert the user to the presence of uninsulated “dan-

gerous voltage” within the product’s enclosure that may be of suffi-

cient magnitude to constitute a risk of electric shock to persons.

The exclamation point within an equilateral triangle is intended to alert the

user to the presence of important operating and maintenance

(servicing) instructions in the literature accompanying the product.

Do not place this unit on an unstable cart, stand or tripod,
bracket or table. The unit may fall, causing serious injury to a
child or adult and serious damage to the unit. Use only with a
cart, stand, tripod, bracket or table recommended by the man­ufacturer or sold with the unit. Any mounting of the device on a
wall or ceiling should follow the maufacturer’s instructions and
should use a mounting accessory recommended by the manu­facturer.

An appliance and cart combination should be moved with care. Quick stops,
excessive force and uneven surfaces may cause the appliance and cart combi­nation to overturn.

Read and follow all the safety and operating instructions before connecting or
using this unit. Retain this notice and the owner’s manual for future reference.

All warnings on the unit and in it’s operating instructions should be adhered to.
Do not use this unit near water; for example, near a bath tub, washbowl, kitchen

sink, laundry tub, in a wet basement or near a swimming pool.
The unit should be installed so that its location or position does not interfere with

its proper ventilation. For example, it should not be situated on a bed, sofa, rug
or similar surface that may block the ventilation openings; or placed in a built-in
installation, such as a bookcase or cabinet, that may impede the flow of air
through its ventilation openings.

The unit should be situated from heat sources such as radiators, heat registers,
stoves or other devices (including amplifiers) that produce heat.

The unit should be connected to a power supply outlet only of the voltage and
frequency marked on its rear panel.

The power supply cord should be routed so that it is not likely to be walked on or
pinched, especially near the plug, convenience receptacles, or where the cord
exits from the unit.

Unplug the unit from the wall outlet before cleaning. Never use benzine, thinner
or other solvents for cleaning. Use only a soft damp cloth.

The power supply cord of the unit should be unplugged from the wall outlet when
it is to be unused for a long period of time.

Care should be taken so that objects do not fall, and liquids are not spilled into
the enclosure through any openings.

This unit should be serviced by qualified service personnel when:
A. The power cord or the plug has been damaged; or

B. Objects have fallen, or liquid has been spilled into the unit; or
C. The unit has been exposed to rain or liquids of any kind; or
D. The unit does not appear to operate normally or exhibits a marked change in
performance; or
E. The device has been dropped or the enclosure damaged.

DO NOT ATTEMPT SERVICING OF THIS UNIT YOURSELF.
REFER SERVICING TO QUALIFIED SERVICE
PERSONNEL.

Upon completion of any servicing or repairs, request the service shop’s assur­ance that only Factory Authorized Replacement Parts with the same characteris­tics as the original parts have been used, and that the routine safety checks
have been performed to guarantee that the equipment is in safe operating condi­tion.
REPLACEMENT WITH UNAUTHORIZED PARTS MAY RESULT IN FIRE,

ELECTRIC SHOCK OR OTHER HAZARDS.

ATTENTION

POUR ÉVITER LES CHOC ELECTRIQUES, INTRODUIRE LA LAME
LA PLUS LARGE DE LA FICHE DANS LA BORNE CORRESPON­DANTE DE LA PRISE ET POUSSER JUSQU’AU FOND.

CAUTION

TO PREVENT ELECTRIC SHOCK MATCH WIDE BLADE OF PLUG
TO WIDE SLOT FULLy INSERT.

If an indoor antenna is used (either built into the set or installed separately),
never allow any part of the antenna to touch the metal parts of other electrical
appliances such as a lamp, TV set etc.

CAUTION

POWER LINES

Any outdoor antenna must be located away from all power lines.

OUTDOOR ANTENNA GROUNDING

If an outside antenna is connected to your tuner or tuner-preamplifier, be sure
the antenna system is grounded so as to provide some protection against volt­age surges and built-up static charges. Section 810 of the National Electrical
Code, ANSI/NFPA No. 70-1984, provides information with respect to proper
grounding of the mast and supporting structure, grounding of the lead-in wire to
an antenna discharge unit, size of grounding conductors, location of antenna dis­charge unit, connection to grounding electrodes and requirements for the
grounding electrode.

a. Use No. 10 AWG (5.3mm2) copper, No. 8 AWG (8.4mm2) aluminium, No. 17
AWG (1.0mm2) copper-clad steel or bronze wire, or larger, as a ground wire.
b. Secure antenna lead-in and ground wires to house with stand-off insulators
spaced from 4-6 feet (1.22 - 1.83 m) apart.
c. Mount antenna discharge unit as close as possible to where lead-in enters
house.
d. Use jumper wire not smaller than No.6 AWG (13.3mm2) copper, or the equiva­lent, when a separate antenna-grounding electrode is used. see NEC Section
810-21 (j).

EXAMPLE OF ANTENNA GROUNDING AS PER NATIONAL ELECTRICAL
CODE INSTRUCTIONS CONTAINED IN ARTICLE 810 - RADIO AND TELEVI­SION EQUIPMENT.

NOTE TO CATV SYSTEM INSTALLER: This reminder is provided to
call the CATV system installer’s attention to Article 820-22 of the
National Electrical Code that provides guidelines for proper grounding
and, in particular, specifies that the ground cable ground shall be con­nected to the grounding system of the building, as close to the point of
cable entry as practical.

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CAUTION

RISK OF ELECTRIC

SHOCK DO NOT OPEN

A TTENTION:

RISQUE DE CHOC ELECTRIQUE

NE PAS OUVRIR

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,

DO NOT REMOVE COVER (OR BACK). NO USER

SERVICEABLE PARTS INSIDE. REFER SERVICING TO

QUALIFIED SERVICE PERSONNEL.

IMPORTANT SAFETY INSTRUCTIONS

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REAR PANEL CONNECTIONS

FRONT PANEL CONTROLS

INTRODUCTION TO THE NAD-911 DIS­TRIBUTION PREAMPLIFIER.

The NAD-911 Distribution Preamplifier has been
designed to control sound in multi-room or multi­speaker installations where both music and messag­ing is required. It will take mono or stereo signals
from a mixer or hi-fi preamplifier and control the distri­bution of sound in up to six separately controllable
speaker zones. Each level control will alter the vol­ume of one particular speaker zone so that the sys­tem can deliver music at different levels in different
areas of the installation. With the built-in microphone
section, the NAD-911 can selectively deliver
announcements and messages to individual parts of
the system.

Several NAD-911s can be connected together to
control music and messages in larger installations.
With a range of internal configuration presets, the
NAD-911 has the flexibility to be configured to match
the needs of most setups.

This manual outlines the use of the NAD-911 in the
most common types of installation. The unit can also
be configured for a wide range of specialist setups
and a qualified installation engineer will be able to
advise on connecting and configuring the NAD-911
within more complex installations.

IMPORTANT INFORMATION.

The NAD- 911 should be placed on a firm level sur­face. Dampness can damage electronic components,
so the unit should not be placed in areas of high
humidity or where liquid could be splashed on it or
spilt over it.

If liquid is spilt over the unit then disconnect from
the AC socket and have the unit inspected by quali­fied service personnel before attempting to use it
again.

The NAD-911 uses standard RCA and 1/4” jack
connections and it is recommended that you use high
quality connectors and cables throughout the installa­tion as this will improve the reliability and the overall
performance of the system.

If the unit is not going to be used for some time,
disconnect the power plug from the AC socket.

There are installation presets inside the unit and
these should be adjusted by qualified installation per­sonnel only. Ensure the top cover is securely
replaced before using your NAD Distribution
Preamplifier.

CLEANING.

Use a soft cloth to clean the NAD-911. If neces­sary, lightly dampen the cloth with soapy water. Do
not use solutions containing benzol or other volatile
agents.

REAR PANEL CONNECTIONS.

1.MIC IN

Input for a Microphone. This Input is suitable for

most medium to high impedance microphones.

The microphone circuitry has a bass roll-off filter
that will reduce low frequency microphone handling
noises being passed to the speakers. A limiter has
been added to the microphone circuit to reduce over­load distortion on very loud sounds. The Microphone
is selected by using the front panel MASTER INSERT
button (6) together with the individual channel
INSERT buttons (4) and adjusting MICROPHONE
LEVEL control (5). Plugging in a microphone into this
socket automatically switches off the LINE INSERT
IN connector.

2.LINE INSERT IN

Input for a line level source. This is used as an

alternative to the microphone for message sources
such as pre-recorded announcements. This is only
active when MIC IN is unused. The MIC IN and LINE
INSERT IN signal can be at a fixed or variable level
depending on the settings of the internal configuration
presets.

3.MIC LINE OUT

Direct output for the microphone signal. The NAD­911 amplifies the microphone input to line level so it
can be used as the microphone feed to additional
NAD-911s in a larger installation. The output of this
socket can be at a fixed or variable level depending
on the settings of the internal configuration presets.

4.INPUT (CHANNELS 1 -6)

Line level inputs for each of the six channels.

These can be connected to any type of audio system
such as a hi-fi preamplifier, cassette deck, CD player,
mixer or the audio outputs of a video player. For
mono sources use a single channel, for stereo
sources use two adjacent channels.

5.FIXED OUT (CHANNELS 1-6)

Direct output for each channel. The level of the

signal on this connector remains the same regardless
of the front panel level controls. The INSERT signal
does not appear on the FIXED OUT connections. The
level is suitable for driving standard hi-fi components
and amplifiers and can be used with leads up to 1nF
total capacitance.

6.VARIABLE OUT (CHANNELS 1-6)

Direct output for each channel. The level of the

signal on this connector is altered by the front panel
LEVEL controls (5). The INSERT signal will appear
mixed on the VARIABLE OUT connections when
selected by pressing the INSERT buttons. At its high­er settings of the LEVEL control, this output will drive
professional (20dBu/600ohm) amplifiers. The variable
output has a low impedance so it can be used to
drive long cable runs up to 22nF total capacitance.

7.POWER CABLE

Fixed power AC cord for connection to AC socket.

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NAD 911 DISTRIBUTION PREAMPLIFIER

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FRONT PANEL CONTROLS.

1.POWER

Power switch to turn the NAD-911 on or off.

2.POWER LED

Indicates that the unit is on.

CHANNELS 1 - 6.

3.LEVEL

Adjusts the volume of each individual speaker

channel.

4. INSERT

Allows the Insert Signal (MIC IN or LINE INSERT

IN) to be included on this particular speaker channel

MICROPHONE.

5.LEVEL

Adjusts the overall volume of the Insert signal from

the MIC IN or LINE INSERT IN sockets.

6.MASTER INSERT

Press to switch the Insert signal on. Press out to

completely disable the Insert signal on all channels.

PREAMPLIFIERS, AMPLIFIERS AND
MIXERS FOR USE WITH THE NAD-911.

In most installations using the NAD-911, the hi-fi
preamplifier is used to select the appropriate music
source and for every-day adjustment of the music vol­ume in the venue.

Any hi-fi preamplifier can be used with the NAD­911 or alternatively an integrated hi-fi amplifier can be
used providing it has a ‘pre-amp’ output. NAD sup­plies a range of preamplifiers and integrated ampli­fiers suitable for use with the NAD-911.

Some installations will use a mixer instead of a pre­amp and this is connected and used with the NAD­911 in exactly the same way as a preamplifier.

The channel outputs of the NAD-911 will work with
both hi-fi and professional power amplifiers. There is
a range of NAD single channel, stereo or multi-chan­nel power amplifiers that are suitable to work with the
NAD-911.

You should ensure that the power output level of
the power amplifiers used in the installation matches
the capabilities of the loudspeakers. If you are using
a power amplifier with its own volume control, during
installation set the NAD-911 LEVEL controls (3) to
the 12 O’clock position and then adjust the power
amplifier’s volume control so that the sound level
from the speaker is about right for normal use.

CABLES.

The amplifiers can be placed near the NAD-911
using short signal leads and long speaker leads.
Generally you will get better performance from the
installation if the amplifiers are placed nearer the
speakers using longer signal leads and shorter
speaker leads. In either case to achieve best perfor­mance all speaker cables should be high quality large
diameter speaker cables (16 gauge or more) and all
signal leads should be high quality co-axial cable.

Cable lengths of up to 22nF total capacitance can

be used to connect the NAD-911 Variable Output to
an amplifier.

CONNECTING INPUTS.

A simple installation uses a CD player and
Cassette Deck connected to the hi-fi preamplifier. In a
stereo system the hi-fi preamplifier is connected to
INPUT sockets (4) of Channels 1 & 2 of the NAD-

911. In a mono system connect the preamplifier to
the INPUT of Channel 1 only.

Connect the Microphone to the MIC IN (1).

LINKING CHANNELS.

Feeding the music signal to every channel in the
distribution preamplifier is done by using links
between the outputs of each channel to the inputs of
the other channels.

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Using the short RCA leads supplied, connect the
FIXED OUTPUT (5) of Channels 1 and 2 to the
INPUT (4) of Channels 3 & 4. Then connect the
FIXED OUTPUT of Channels 3 & 4 to the INPUTs of
Channels 5 & 6. (In a mono system connect Channel
1 FIXED OUTPUT to Channel 2 INPUT etc.)

CONNECTING OUTPUTS.

Connect the VARIABLE OUT sockets (6) of each
channel to the appropriate power amplifier and
speaker system. The power amplifiers and loud­speakers should be matched with respect to power
and quality. NAD supplies a range of power and inte­grated amplifiers suitable for use in these types of
installations.

SETTING THE MUSIC LEVEL.

Set the hi-fi preamplifier volume control to mini­mum. Set the NAD-911 MICROPHONE LEVEL con­trol (5) to minimum and the rest of the Channel
LEVEL controls (3) to the 12 O’clock position. Switch
the system on.

With a music source playing (preferably a CD) turn
the preamplifier volume control up until the music
reaches a generally acceptable level. Now adjust
each of the individual speaker volumes to exactly the
required level by adjusting each of the NAD-911
channel LEVEL controls (3).

SETTING THE MICROPHONE LEVEL.

Switch off the music source. Set the MICRO­PHONE LEVEL control (5) to minimum. Press the
MICROPHONE MASTER INSERT button (6) in and
the INSERT buttons (4) on all channels. Speak into
the microphone whilst slowly turning up the MICRO­PHONE LEVEL control (5) until the announcement
level is about right. Switch the music source on and
fine adjust the MICROPHONE LEVEL. Switch out the
MICROPHONE MASTER INSERT button when fin­ished.

BASIC OPERATION.

The NAD-911 is used primarily as an installation
tool to distribute and accurately set up the sound lev­els in all parts of the venue. So in general daily oper­ation, adjust the music source and overall level using
the hi-fi preamplifier controls only.

INSERT SIGNAL TO ALL CHANNELS

In a simple installation, where all the channels are
linked together, press the INSERT (4) button on all
channels. Announcements will be fed to all speakers
whenever the microphone is used and the MASTER
INSERT button is pressed.

INSERT SIGNAL ONLY ON SELECTED
CHANNELS

Press the INSERT buttons (4) only on the channels
where announcements are required. Announcements
will be fed to those speakers whenever the micro­phone is used and the MASTER INSERT button is
pressed.

Only the channels with the INSERT buttons
depressed will be fed with the announcements when
the microphone is used and the MASTER INSERT
button is pressed. If announcements are to be fed
only to specific channels then press the INSERT (4)
buttons on only those channels which need
announcements.

NOTE:

The microphone Insert signal can be configured
internally to be disabled, inserted before or after
either one of the six channel level controls. The facto­ry default setting inserts the signal before the level
control for all channels. Changing the configuration
must be left to qualified personnel.

USING MIC LINE OUT

As well as feeding the Microphone signal internally
to each channel using the Insert function, there is a

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BASIC CONNECTION AND OPERATION.

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separate microphone signal output, the MIC LINE
OUT (3).

This output carries the microphone signal amplified
to line level. It can be used to feed the microphone
signal to further external units such as a second
NAD-911 or to link in with other separate sound
installations.

USING SEVERAL NAD-911s.

The outputs of the main distribution preamplifier are
connected to the first channels of the second unit to
feed it with the music signal.

Use the main NAD-911’s MIC LINE OUT (3) to
send the microphone insert signal to the second
unit’s LINE INSERT IN (2) socket. This will ensure
you maintain full control over which speaker channels
get fed with the announcements and at what level.

NOTE: In the factory default setting, the Mic Line

Out signal level is linked with the Microphone Level
control (5) on the front panel. The NAD 911 configu­ration can be changed so that the Mic Line Out signal

level is fixed, independent from the Microphone Level
Control. Changing the configuration must be left to
qualified personnel.

TAMPER-PROOF COVERS.

If the system is to be installed so that its level set­tings do not need to be changed in normal operation,
then use the Tamper-proof Covers included with your
NAD-911 to stop accidental use of the LEVEL con­trols and/or INSERT buttons. Fitting it with the Insert
Button section of the cover to the right, will protect
both the level settings and the insert button settings.
Using the cover with the insert button section to the
left leaves the insert button available.

Remove the volume control on any channels that
need tamper-proofing, by gently pulling the LEVEL
knob off its spindle.

Gently push the Tamper-proof Cover in the opening
left by the volume control knob. Ensure that the two
small legs on the Tamper-proof cover line up with the
two holes in the sub-facia behind the front panel.

SERVICING, INSTALLATION AND CON­FIGURATION INTRUCTIONS

CAUTION:

These servicing and installation
instructions are for use by qualified personnel
only. To reduce the risk of electric shock do not per­form any servicing other than that contained in the
operation instructions unless you are qualified to do
so. Refer all servicing to qualified service person-

nel.

CAUTION: Before removing the top cover dis-

connect the unit from the mains supply.

INSERT SYSTEM CONFIGURATION.

Altering jumpers inside the unit can change the
way the insert and variable level functions work so
that the NAD-911 can be configured to meet the
messaging requirements of the system. This must
be done by qualified personnel only.

WHY USE DIFFERENT INSERT SETTINGS?

Whilst the basic function of accurately setting the
music levels to individual speakers is generally the
same in all installations, the announcement require­ments may vary enormously. The Insert configura­tion allows installers to match the operation of the
NAD-911 exactly to the announcement needs of the
user.

MICROPHONE LINE OUT LEVEL, FIXED OR
VARIABLE.

If the system is being used in an area where the
music level needs to be varied as the background
noise varies,then the announcement levels should
also go up or down with the music level. This
ensures that the announcements will be heard over
the music and general background noise in the area.
In this situation the insert function of each channel
should be set to Insert Variable.

If the system is being used in an office or shop
type of venue where the music level is only occa­sionaly altered and set to low background level, then
the Microphone level needs to be set up so that
announcements can be heard clearly but are not too
loud. Setting all channels to Insert Fixed helps to
ensure that the correct announcement levels are
maintained.

Some areas of the installation may never need
announcements. Configure the channels feeding the
speakers in these areas to Insert Disabled to ensure
that announcements are not accidentally routed to

these areas.

CONFIGURING THE NAD-911 INTERNAL
JUMPERS.

With the unit unplugged from the AC socket,
remove the lid by removing the 5 screws securing
the top panel. When the 911 has been configured
securely replace the unit’s top panel.

FIXED OR VARIABLE MICROPHONE LINE
OUT LEVEL.

In most installations using multiple NAD 911, it will
be desirable to give the first 911 control over the
microphone level for all 911s in the system. In this
case the first 911 should be set to Variable and all
following 911s should be set to Fixed. This way the
second and subsequent 911s will not alter the
Microphone Line out level to the next 911.

Change jumper JP25 from the factory default set­ting ‘VARIABLE’ to the ‘FIXED’ position.

CONFIGURING MICROPHONE AND MUSIC
LEVELS.

Each channel can be configured individually so
that the Microphone or Line Insert volume level will
always be the same regardless of the individual
channels level setting. Alternatively the channel can
be configured so that the Microphone level is linked
to the level of the music. Turning up the channel’s
level control will then also turn up the volume of the
microphone.

A third setting switches off the microphone signal
from that channel completely.

NOTE: For all channels the factory default is set to

Variable.

FIXED MICROPHONE LEVEL.

To set up the channel so that the level of the
Inserted signal (Microphone or pre-recorded mes­sage) to be at a preset level no matter what the indi­vidual channel volume setting is.

Set the four jumpers for that channel to INS
FIXED.

LINKING MICROPHONE AND INPUT

LEVELS.

To set up the channel so that the channel level
control alters the volume of both the music and insert
levels. Set the four Jumpers for that channel to INS
VARIABLE.

DISABLING MICROPHONE INSERT ON A
CHANNEL.

If you don’t want the Insert signal to ever appear
on a particular channel. Set the channel’s first two
jumpers (JP -01 and JP -02) to INS FIXED and set
the second two jumpers (JP -03 and JP -04) to INS
VARIABLE

CAUTION: Do not use any other configuration of

the jumpers.

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CONFIGURATION SETTINGS.

Use this table to keep a note of the NAD-911 set-

tings.
NAD 911 Ser. no:

Unit location...................................

Date..................

Channel 1: Variable ___ Fixed ___ Disable ___
Channel 2: Variable ___ Fixed ___ Disable ___
Channel 3: Variable ___ Fixed ___ Disable ___
Channel 4: Variable ___ Fixed ___ Disable ___
Channel 5: Variable ___ Fixed ___ Disable ___
Channel 6: Variable ___ Fixed ___ Disable ___

Microphone Line Out: ___ Variable Fixed ___