E3
NAC 552
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 5.2 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 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 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 following paragraphs describe installation features and functions specific to the NAC 552.
Operational features common to all preamplifiers are described in Section 14.
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 NARCOM 4 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 are
described in Section 14.
