Naim Audio NAC-N 172 XS - Manual (Page 5)

E3
NAC 552 Preamplifier
4 NAC 552 Introduction and Installation
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 5.3 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.
The preamplifier and power supply should be installed on a dedicated equipment
stand intended for the purpose. Do not stand either directly on top of another item of
equipment. Care should be taken to ensure that the preamplifier is level.
The preamplifier and power supply should be installed in their final locations before
connecting cables or switching on. Ensure that power amplifiers are switched off and
that the preamplifier volume is turned down before the power supply is switched on. The
power button is located on the power supply front panel.
The units are heavy and care should be taken when lifting or moving them. Make sure
that the surface on which they are to be placed can support their weight.
The following Section 4 paragraphs describe installation features and functions specific to
the NAC 552. Operational features common to all preamplifiers and integrated amplifiers
are described in Section 28.
Both R-Com and NARCOM 4 remote handsets are included with the NAC 552. The R-com
is intended for day-to-day use while the NARCOM 4 can be used for handset-based setup
and programming.
4.1 Source Inputs and Record Outputs
The input selection 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, is 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.
4.2 Input Socket Assignment
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 assignment could enable any input
socket to be selected by pressing the CD button. Assigning
of each record button follows the corresponding source
button.
Input assignment setup is accessed through the NAC
552
program mode . To switch into (or exit from) 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 front panel volume control and the
record selection indicators extinguishing.
Note: 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
assigned 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
assigned.
To change the input socket assigned 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 assigned to a source
button the indicator above the socket will flash repeatedly.
It is possible to assign one input socket to more than one
source button but NOT to assign multiple input sockets to
one source button. The remote handset
record mute and
mono functions can also be used to set up input assignment.
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.
Table 4.3 illustrates the NAC 552 default input assignment.
Operational features
common to all
preamplifiers and
integrated amplifiers
are described in
Section 28