Digital And Analogue Pre-Amplifier Outputs; Set-Up And Initialisation; System Sensitivity Switch - NAD 118 Manuel D'installation

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DIGITAL & ANALOGUE PRE-AMPLIFIER OUT-
PUTS (2 & 15)
The Model 118 can drive a power amplifier direct,
using its high quality, built-in DAC. It is also possible to
use an external DAC which in turn drives a power
amplifier or active loudspeakers. There are loudspeak-
ers available which have a built-in DAC and power
amplifiers. In such a case, always use the Digital Pre-
amp out (2).
Analogue Pre-amp Out (15):
Connect the input of a power amplifier or active loud-
speakers in these jacks (normally labeled as LINE IN,
MAIN IN, POWER IN, etc.). Ensure Left and Right
channels are properly connected.
Digital Pre-amp Out (2):
Connect the input of a separate DAC or loudspeak-
ers with built-in DAC to this jack (labeled as DIGITAL
IN, COAX IN, etc.).

3. SET-UP AND INITIALISATION

Before the NAD Model 118 can be operated it might
be necessary to adjust the Input Gain for the analogue
inputs and the pre-amp's output level (System
Sensitivity) to match the rest of the system in which it
will be used. To obtain optimum performance it is rec-
ommended to go through the following procedures and
adjust where necessary.
GAIN
It is important that the input gain of the Model 118's
selected source and the output level of the correspond-
ing analogue source match up. If the output level from
the source is too high (input gain is set too high) then
the Model 118's ADC will be overloaded which will
cause distortion at loud passages. Alternatively, if the
output level from the source is too low (input gain is set
too low) you will not get the maximum benefit of the
high resolution and sound quality the Model 118 has to
offer.
The input gain (sensitivity) can be set individually for
all 4 analogue sources. There are 4 different selectable
input levels for each analogue input: 0dB; -5dB, -10dB
and -15dB, indicated by the 2 amber LEDs (3 on front
panel drawing). With these 4 levels available it is pos-
sible to accommodate virtually all analogue line-level
sources. The PEAK indicator (23 in front panel draw-
ing) above the volume control gives a visual indication
of when the level has been set correctly. To set the cor-
rect input sensitivity:
1. For the appropriate source, select some music
with high dynamic and loud passages (Full orchestra
on CD, loud radio station, action scene on video, etc.)
2. Select the analogue source for which you wish to
adjust the gain (input sensitivity) by pressing either
Disc, Tuner, Video or Tape (4,5,6 or 7) and play back
the pre-selected loud passage.
3. Check the PEAK LED (23) to see if it illuminates. If
it illuminates almost continuously then the level is too
high (and sensitivity must be reduced), if it doesn't light
up at all then the level is almost certainly too low (sen-
sitivity must be increased). If the PEAK LED lights up
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8
for a fraction of a second every few seconds the level is
set correctly.
4. At moderate volume level, press the same source
button and keep it pressed down whilst turning the vol-
ume control downwards to decrease input sensitivity or
upwards to increase sensitivity. Only a slight turn of the
volume control is required to change the input gain.
The GAIN LEDs (3 on the front panel) give an indica-
tion of the input sensitivity level set:
GAIN GAIN
GAIN
-5dB -10dB -5dB -10dB -5dB -10dB
A B C
A. Level set at 0dB (High gain) B. Level set at -5dB
(Normal/high gain) C. Level set at -10dB (Normal/low
gain D. Level set at -15dB (Low gain)
5. Once the correct level is set (refer to No. 3 of this
section) release the input select button. The setting will
be retained for each of the 4 individual inputs even if
the unit has been switched off for some time.
NOTE: The Model 118 factory default setting is at -
15dB for all analogue inputs.
NOTE: Although both Tape Checks (8 & 13) are
analogue inputs, gain cannot be adjusted for these.
Gain for these inputs corresponds with 0dB Gain set-
ting for the other analogue inputs

SYSTEM SENSITIVITY SWITCH (16)

Each HiFi system is different; the power amplifier can
have more than usual gain (power amp needs little sig-
nal to be able to deliver full power) or the loudloud-
speakers can be of a high efficiency type (the loud-
speakers need relatively little power to produce high
volume levels). In such circumstances it is possible to
decrease the Model 118's output signal. To set the
switch to the correct position:
1. Select a piece of music with many loud passages.
2. Turn down the volume and switch on the High
Gain (21 on the front panel).
3. Select the "Normal" position of the System
Sensitivity switch (16 on the back panel).
4. Select the appropriate input and play back the pre-
selected music.
5. Turn up the volume so that the music plays at
maximum sustainable level without signs of stress from
the power amplifier or loudspeakers.
6. If maximum sustainable loudness is obtained with
the volume control before the 11 o'clock position, press
the System Sensitivity switch (16 on the back panel) to
engage the "High" position (switch protrudes more).
Turn the volume down to a normal level before press-
ing the System Sensitivity switch.
Some power amplifiers and active loudloudspeakers
are fitted with "input gain", "sensitivity" or "volume" con-
trols. In such a case select the "Normal" position for the
System Sensitivity switch and adjust the controls on the
power amplifier or active loudspeakers accordingly.
If you find that during normal playback the volume
control consistently has to be set at the 12 o'clock posi-
GAIN
-5dB -10dB
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