NAC-52
O W N E R S M A N U A L
P r e a m p l i f i e r s
1.0 Equipment installation
1
Normally your Naim equipment will have been installed by the dealer who sold
it to you even if you live outside their immediate vicinity. Your dealer is
responsible for making sure that the system sounds exactly as it should and
information given here is not intended to reduce this responsibility in any way.
page
1 1.0 Equipment Installation
1.1 cables and
connections
2 2.0 Getting Started
2.1 switching on and off
2.2 running in
2.3 mains supply
2.4 siting the equipment
2.5 if you have a problem
3 3.0 Warnings
4 4.0 Connection
4.1 mains lead
4.2 non-rewireable mains
plugs
4.3 fuse carrier
4.4 plug fuses
5 nac 52
8 nac 82
12 nac 102
15 nac 112
18 narcom 2 remote handset
20 EC Declaration of Conformity
to Appropriate Standards
1.1 cables and connections
Please do not modify the standard interconnect cables supplied with your Naim
equipment. This is important for safety as well as performance. One end of each
cable is marked with a band to establish its correct orientation. The band always
marks the end that connects to the signal source.
Loudspeaker leads are also very important. Naim loudspeaker cable is correct for
your system and your dealer will make up leads to suit your equipment
installation. The leads should each be at least 3.5 metres long and of equal
length. The recommended maximum is 20 metres. Loudspeaker leads are, like
interconnect leads, directional, and should be connected so that the printed
arrow points towards the speakers. Using alternative loudspeaker cable will
degrade performance, and may even damage your amplifier. An exception to
these loudspeaker cable constraints is the nap 6-50 multi-room power
amplifier. The nap 6-50 is designed to be tolerant of both a wide variety of cable
types, and cable runs well in excess of 20m. The loudspeaker connectors supplied
with all Naim amplifiers and loudspeakers have been specifically designed to
make a robust mechanical connection. It is essential that these are used in order
to comply with current European safety regulations.
All the plugs and sockets supplied with your Naim equipment have been chosen
because they make the best possible connection for their purpose. A poor
contact will degrade the signal substantially and plugs and sockets should look
clean and free from corrosion. The easiest way to clean them is to switch off the
equipment, pull the plugs out of their sockets, and push them back in again.
Special contact cleaners and contact enhancers should not be used as they tend
to deposit a film which is very difficult to remove and may degrade the sound.
2.0 Getting Started
2.1 switching on and off
Source components and power supplies for cd players, tuners, preamplifiers and crossovers
should be switched on before switching on the amplifier(s). Always switch the amplifier(s)
off and wait about a minute for its power supply capacitors to discharge before
connecting or disconnecting any leads. Always use the power switch on the product rather
than a mains outlet switch.
2.2 running in
Your Naim equipment will take a considerable time to run-in before it performs at its best.
The duration varies, but under some conditions you will find that the sound continues to
improve for as much as five weeks. Better and more consistent performance will be
achieved if the system is left switched on for long periods. It is worth remembering
however that all electronic equipment can be damaged by lightning. Please read the
warnings section.
2.3 mains supply
Where fused plugs are used 13 amp fuses should be fitted. Fuses of a lower rating will fail
after a period of use.
A hi-fi system usually shares a mains circuit with other household equipment some of
which can cause distortion of the mains waveform. In some Naim equipment such
distortion can lead to a mechanical hum from the transformers. The hum is not
transmitted through the speakers and has no effect on the performance of the system but
is purely local to the transformer itself. A separate fused mains circuit (like that reserved
for electric cookers) may reduce transformer hum. Such a circuit (ideally with a 30 or 45
Amp rating) will also have a lower impedance, supply cleaner power, and consequently
improve system performance.
Do not wire voltage dependent resistors or noise suppressors into mains plugs. They
degrade the mains supply and the sound.
2.4 siting the equipment
Power supplies and amplifiers should be located a reasonable distance away from other
equipment. This separation will stop transformer radiation causing hum audible from the
loudspeakers. The minimum recommended distance is 300mm (12 inches), and that
allowed by the standard interconnect lead is the maximum.
Some Naim equipment is extremely heavy. Ensure than your equipment rack or table can
easily support the weight and is stable.
2.5 if you have a problem
Legal consumer protection varies from country to country. In most territories a dealer
must be prepared to take back any Naim equipment he has sold you if he cannot make it
work to your satisfaction in your own home. A problem may be due to a fault in any part
of the system or its installation so it is essential to make full use of your local dealer’s
diagnostic skills on site. Please contact your local distributor, or Naim at the address in
the back of this manual, if any difficulties cannot be resolved. Some Naim equipment is
made in special versions for different territories and this makes it impracticable to arrange
international guarantees. Please establish the guarantee arrangements with your own
dealer at the time of sale. We are always available to offer help and advice.
It is essential that repairs and updates are only carried out by an authorised Naim dealer,
or at the factory by Naim itself. Many components are made, tested or matched specially
for Naim and appropriate replacements are often unobtainable from non-specialist
sources.
2
3.0 Warnings
Naim equipment is designed to offer the finest sound quality that can be achieved,
avoiding compromise wherever possible. This can lead to circumstances that may be
unfamiliar. The material that follows contains advice specifically related to Naim
equipment as well as more general warnings about the use of domestic audio products.
Please read it carefully.
The transformers in Naim power amplifiers and power supplies may sometimes make a
mechanical noise caused by distortion of the mains waveform. Naim transformers are
large in size and have heavy gauge secondary windings making them relatively sensitive
to such distortion. A separate mains circuit for your hi-fi system may reduce the effect
while also giving an overall improvement in sound quality. It may be necessary however
to take account of mechanical transformer noise when siting your equipment.
In some circumstances, depending on where you live and the earthing arrangements in
your home, you may experience radio frequency interference. Controls on broadcasting in
some territories allow very high levels of radio frequency radiation and both the choice
and exact siting of equipment may be critical. If there is a known problem in your locality
it is advisable to arrange for a home demonstration before purchase to find out if Naim
equipment is likely to be affected. Susceptibility to radio frequency interference is related
to the wide internal bandwidth necessary for high sound quality. Systems incorporating
moving coil phono preamplifiers and active crossovers are more likely to suffer. A radio
frequency filter kit is available for some Naim equipment but sound quality will be
progressively compromised as more elements of the kit are fitted. In situations of extreme
radio interference Naim equipment may be unsuitable.
Your Naim hi-fi system can be damaged by lightning. Power amplifiers are particularly at
risk and should be turned off when there is risk of lightning strike. For complete protection
all mains plugs and any aerial cables should be disconnected when not in use.
Equipment must not be exposed to dripping or splashing and no objects filled with liquid,
such as vases, should be placed on the equipment.
important
In order to comply with current
European safety regulations it is
essential that the Naim loudspeaker
connectors supplied with amplifiers
and loudspeakers are used.
Do not under any circumstances
allow anyone to modify your Naim
equipment without first checking
with the factory, your dealer, or
your distributor. Unauthorised
modifications will invalidate your
guarantee.
For your own safety do not under
any circumstances open Naim
equipment without first
disconnecting the mains.
The following label is attached to
all mains powered equipment:
3
4.0 Connection
4.1 mains lead
As the colours of the wires in the mains lead of this apparatus may not correspond with
the coloured markings identifying the terminals in your plug proceed as follows:
The wire which is coloured GREEN-AND-YELLOW must be connected to the terminal in
the plug which is marked by the letter E or by the safety earth symbol or coloured green
or green-and-yellow.
The wire which is coloured BLUE must be connected to the terminal in the plug which is
marked with the letter N or coloured black.
The wire which is coloured BROWN must be connected to the terminal in the plug which
is marked with the letter L or coloured red.
4.2 non-rewireable mains plugs
If a non-rewireable plug is cut from a mains lead (for whatever purpose) the plug MUST
be disposed of in a way to render it totally unusable. Considerable shock hazard exists if
the cut-off plug is inserted into a mains outlet.
4.3 fuse carrier
Should the plug fuse carrier be damaged or lost, the correct replacement must be obtained
from your dealer or from Naim direct. Do not use the plug until the fuse carrier is replaced.
4.4 plug fuses
Replace only with ASTA or BS 1362 approved fuses.
note
This equipment has been tested and found to comply with the relevant EMC and Safety Standards,
and, where applicable, also complies with the limits for a class B digital device, pursuant to Part
15 of the FCC Rules.
These limits are designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses and can radiate radio frequency and, if not
installed and used in accordance with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not occur in a particular
installation. If this equipment does cause harmful interference to radio or television reception,
which can be determined by turning off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and the receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
• Consult your Naim dealer or an experienced radio/TV technician for help.
4
nac 52 operation
power supplies
The nac 52 does not incorporate an internal power supply and can be used only in conjunction with a
supercap power supply.
listening and recording
The input selector buttons are arranged along the uppermost bank of buttons. They control which
source is to be routed to the power amplifier and the loudspeakers, for listening. Below them, in the
lower bank, are a corresponding array of buttons which choose the source component to be routed to
the preamplifier’s recording outputs. One component (for example, the record player) can therefore be
listened to whilst the output from another (say, the tuner) can be recorded onto a tape recorder. It is
possible to lock the record controls and prevent accidental de-selection during recording. Record-lock
is switched on or off by depressing the source mono button four times within six seconds.
mute and mono facilities
To the left of each bank of buttons there are two further buttons labelled mute and mono. These work
independently: for example the mute button in the lower (recording) bank does not affect the signal
that is chosen via the upper (source) buttons, and vice versa. Operating the mono button on the source
bank will not affect the record circuits. To select either function press the relevant button once. To
cancel that function press the button again.
preamplifier inputs
Input 1 is a high level input, but can be converted into a phono input by fitting plug in boards. Please
see your dealer for further details.
Input 2 is a standard high level input. Before using, see the section “input socket 2” below.
Input 3 is a standard high level input.
Inputs 4, 5 and 6 are standard high level inputs and also have record output facilities, so these should
be assigned to your tape recorder, cassette deck or VCR.
input socket 2 to expand input capabilities
Please note that input 2 is provided with two sockets. Use socket 2a for connecting your usual
ancillary equipment. The extra socket (2b) is for the Prefix or Stageline phono stage. Only one of these
sockets may be used at a time, for safety as well as performance. Your preamplifier will have a
protective cover fitted over the extra socket. If you wish to use it, it is advisable to refit the protective
cover over the socket that will now be unused, to prevent mistakes.
remote control
For operation of the nac 52 using the NARCOM 2 remote handset please see pages 18 and 19
5
nac 52 front
volume
nac 52 rear
inputs
1 2(a/b) 3 4 5 6
source
record
mute
balance mono
high level inputs
6 5 4 3 2a 2b
audio power supply
digital power supply
inputs 6, 5 & 4 input 2b
ch1
ch2
Specifications
nac 52
High level input sensitivities 75mV, 100k
Phono input options
Moving Magnet N 2mV, 47k
Moving Coil S 100µV, 470
Moving Coil K 100µV, 560
Moving Coil E 400µV, 560
Overload margin (all inputs, all audio frequencies) 40dB
Main output level 0.775V, <50
Tape output level 75mV, 600
Case size (H x W x D) 76 x 430 x 300mm
phono input
ch 1 left ch 2 right
inputs 3 & 2a
ch1
ch2
ch1
-ve
1
phono ground
ch2
-ve
nc
+ve
nc
ch2
+ve
ch1
-ve
6
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