NAIM AMPLIFIERS Owner's Manual - page 5
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NAC 552
5 Installation and Operation
The NAC 552 preamplifier does not incorporate an internal power supply and can be
used only in conjunction with the NAC 552PS power supply. Diagram 6.3 illustrates
connection of the NAC 552 to its power supply.
The four transit screws on the underside of the NAC 552 case should be removed before
use and must be replaced if the unit is to be re-packed and shipped. These transit
screws must not be used in any other Naim product. Do not invert the NAC 552 once the
transit screws are removed.
5.1 Source Inputs and Record Outputs
The input selector buttons arranged along the
upper
bank
select the
source
signal to be routed to the power amplifier
and the loudspeakers. Below them, in the
lower
bank, are a
corresponding array of buttons which select the signal to be
routed to the preamplifier’s
record
outputs.
These separate source and record sections enable one source (a
CD player, for example) to be listened to whilst the output from
another (say, the tuner) is simultaneously selected for recording.
Note:
It is possible to lock the record controls and prevent
accidental de-selection during recording. Record-lock is switched
on or off by pressing the
source mono
button four times within six
seconds.
Indicators are fitted to the NAC 552 rear panel above each input
socket. These indicators illuminate to provide information on
input selection and on input mapping setup and programming.
5.2 Input Socket Mapping (Program Mode)
Any NAC 552 source input socket can be selected by any
button. For example, while the NAC 552 default setup is for
the CD input button to select input socket No. 2, custom
programming of
input mapping
could enable any input socket to
be selected by pressing the CD button. Mapping of each record
button follows the corresponding source button.
Input mapping setup is accessed through the NAC 552 program
mode. To switch into program mode press and hold the
prog
key
on the remote handset (in preamplifier mode). Program mode is
indicated by a flashing indicator on the volume control and the
record select indicators extinguishing. If no function is operated
within five minutes of entering program mode the NAC 552 will
return to normal mode automatically.
Any of the six source buttons on the front panel can be mapped
to any of the nine stereo inputs (seven DIN sockets and two RCA
Phono socket pairs) on the rear panel. In program mode, as a
source input is selected, a rear panel indicator will illuminate to
designate the socket to which it is mapped.
To change the input socket mapped to a source button, select
the source button and use the front panel
record mute
and
mono
buttons to scroll along the input sockets. If the input
socket selected is already mapped to a source button the
indicator above the socket will flash repeatedly. It is possible to
map one input socket to more than one source button but NOT
to map multiple input sockets to one source button. The remote
handset record
mute
and
mono
functions can also be used to
set up input mapping.
To exit from program mode press and hold the
prog
key on the
handset until the record select indicators are restored and the
volume indicator stops flashing.
5.4 Automatic Input Switching
The NAC 552 incorporates an optional automatic input switching
feature which can select the appropriate input as soon as any
handset function for a particular Naim source component is
operated. For example, if the tuner input is selected on the NAC
552 and the CD play key is operated on the handset, the NAC
552 will automatically switch to the CD input. Automatic input
switching can be programmed to operate independently on any
combination of the CD, AV and Tuner input buttons (and sockets
to which they are mapped).
To enable automatic input switching, first switch the NAC 552
into program mode as described in Paragraph 5.2. The front
panel source mono button will illuminate if automatic switching
is already enabled. If it is not enabled it can be switched on by
pressing the
button twice.
With auto switching enabled,
pressing the
source mono
button
will reveal the inputs selected
for auto switching by their button
indicators illuminating for a short
time. Repeated operation of the
source mono
button will sequentially
select through each possible
combination of CD, Tuner, AV inputs,
and auto switching disabled (CD,
Tuner and AV button indicators off).
When the desired inputs selected for
auto switching are indicated, stop
pressing the
source mono
button.
Preamplifier
5.3 Socket Types and Mapping Defaults
Input Socket
Socket
Source Button
Number
Features
Mapping Default
1
DIN input
Not Mapped
2
DIN input
CD
3
DIN input
TUNER
4
DIN input/output, unity gain capable
TAPE
5
DIN input/output, unity gain capable
AV
6
DIN input/output
AUX 1
7
DIN input, power output for Stageline
AUX 2
8
RCA Phono pair
Not mapped
9
RCA Phono pair
Not mapped