NAD 911 Manuel D'installation page 4

GB NAD 911 DISTRIBUTION PREAMPLIFIER
INTRODUCTION TO THE NAD-911 DIS-
TRIBUTION PREAMPLIFIER.
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
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 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
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 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
Preamplifier.
CLEANING.
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
agents.
NAD
4
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 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
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 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
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 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.
7.POWER CABLE
Fixed power AC cord for connection to AC socket.