4
6.1 connections notes
The negative input and output connections for each
channel are common. The mains earth (ground) should
always be connected regardless of what other equipment is
used in conjunction with Naim power amplifiers. This only
grounds the case and the electrostatic screen within the
transformer, and is not connected to the signal negative. In
order to avoid hum loops, the signal negative of the whole
system should be connected to the mains earth (ground) in
one place. This should be the primary signal source.
Note:
Each channel of the NAP 500 is a “bridged”
amplifier, so none of the speaker outlet sockets (+ or -) is
at earth potential. Avoid connecting mains powered
equipment such as electrostatic speakers, sub-woofers and
headphone energisers that do not have a floating earth. No
plug which is connected directly or indirectly to earth
potential should be attached to any speaker outlet (+ or -).
6.2 protection notes
In the NAP 500 the fan speed is increased in response to
an increase in amplifier dissipation. If the amplifier reaches
70°C due to prolonged running at high level or to airflow
being blocked, the output will be interrupted and the fan
will run at full speed until it has cooled down. This may
take a few minutes.
It is not necessary to switch the amplifier off, but it may be
advisable to mute the preamplifier or turn the volume down
to avoid surprises when it comes back on.
OPERATION OF THE AMPLIFIER’S THERMAL PROTECTION
SUGGESTS PROLONGED USE AT TOO HIGH A VOLUME
LEVEL. YOUR LOUDSPEAKERS MAY BE AT RISK IF THIS IS
THE CASE. THE VOLUME SHOULD BE REDUCED.
NAP 500
6 Installation and Operation
The NAP 500 and NA PS500 should be installed in their final operating locations before
connecting cables or switching on. Switch on the source and preamplifier components,
with the volume turned down, before switching on the NAP 500. The NAP 500 power
button is located on the front panel of the NA PS500 Power Supply.
Care should be taken when siting the NAP 500 to ensure that the top and bottom
ventilation grids are not blocked e.g. by carpet if the unit is to be placed on the floor.
The NAP 500 is very heavy and care should be taken when lifting or moving it. Make
sure that the surface it is to be placed on can support the full weight.
6.3 loudspeaker cable and connectors
Only Naim Audio speaker cable should be used to connect
a loudspeaker to the output of the NAP 500. Custom Naim
Audio loudspeaker connectors are supplied to make the
connection.
IN ORDER TO COMPLY WITH CURRENT
EUROPEAN SAFETY REGULATIONS IT IS ESSENTIAL THAT
THESE ARE USED.
DAMAGE TO THE AMPLIFIER MAY RESULT IF “HIGH
DEFINITION” CABLE OR ANY OTHER SPECIAL CABLE IS
USED TO CONNECT THE LOUDSPEAKERS.
