· OWNER'S MANUAL
· MANUEL D'INSTALLATION
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 man-
ufacturer 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 manu-
An appliance and cart combination should be moved with care. Quick stops,
excessive force and uneven surfaces may cause the appliance and cart combi-
nation 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
E. The device has been dropped or the enclosure damaged.
DO NOT ATTEMPT SERVICING OF THIS UNIT YOURSELF.
REFER SERVICING TO QUALIFIED SERVICE
Upon completion of any servicing or repairs, request the service shop's assur-
ance that only Factory Authorized Replacement Parts with the same characteris-
tics 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 condi-
REPLACEMENT WITH UNAUTHORIZED PARTS MAY RESULT IN FIRE,
ELECTRIC SHOCK OR OTHER HAZARDS.
POUR ÉVITER LES CHOC ELECTRIQUES, INTRODUIRE LA LAME
LA PLUS LARGE DE LA FICHE DANS LA BORNE CORRESPON-
DANTE DE LA PRISE ET POUSSER JUSQU'AU FOND.
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.
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 volt-
age 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 dis-
charge unit, connection to grounding electrodes and requirements for the
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
d. Use jumper wire not smaller than No.6 AWG (13.3mm2) copper, or the equiva-
lent, when a separate antenna-grounding electrode is used. see NEC Section
EXAMPLE OF ANTENNA GROUNDING AS PER NATIONAL ELECTRICAL
CODE INSTRUCTIONS CONTAINED IN ARTICLE 810 - RADIO AND TELEVI-
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 con-
nected to the grounding system of the building, as close to the point of
cable entry as practical.
RISK OF ELECTRIC
SHOCK DO NOT OPEN
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
REAR PANEL CONNECTIONS
FRONT PANEL CONTROLS
INTRODUCTION TO THE NAD-911 DIS-
The NAD-911 Distribution Preamplifier has been
designed to control sound in multi-room or multi-
speaker installations where both music and messag-
ing is required. It will take mono or stereo signals
from a mixer or hi-fi preamplifier and control the distri-
bution of sound in up to six separately controllable
speaker zones. Each level control will alter the vol-
ume of one particular speaker zone so that the sys-
tem 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
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.
The NAD- 911 should be placed on a firm level sur-
face. 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 quali-
fied service personnel before attempting to use it
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 installa-
tion 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 per-
sonnel only. Ensure the top cover is securely
replaced before using your NAD Distribution
Use a soft cloth to clean the NAD-911. If neces-
sary, lightly dampen the cloth with soapy water. Do
not use solutions containing benzol or other volatile
REAR PANEL CONNECTIONS.
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 over-
load 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
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
3.MIC LINE OUT
Direct output for the microphone signal. The NAD-
911 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
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 high-
er 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.
Fixed power AC cord for connection to AC socket.
NAD 911 DISTRIBUTION PREAMPLIFIER
FRONT PANEL CONTROLS.
Power switch to turn the NAD-911 on or off.
Indicates that the unit is on.
CHANNELS 1 - 6.
Adjusts the volume of each individual speaker
Allows the Insert Signal (MIC IN or LINE INSERT
IN) to be included on this particular speaker channel
Adjusts the overall volume of the Insert signal from
the MIC IN or LINE INSERT IN sockets.
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 vol-
ume in the venue.
Any hi-fi preamplifier can be used with the NAD-
911 or alternatively an integrated hi-fi amplifier can be
used providing it has a `pre-amp' output. NAD sup-
plies a range of preamplifiers and integrated ampli-
fiers suitable for use with the NAD-911.
Some installations will use a mixer instead of a pre-
amp and this is connected and used with the NAD-
911 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-chan-
nel power amplifiers that are suitable to work with the
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.
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 perfor-
mance 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
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).
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.