NAIM AMPLIFIERS Owner's Manual - page 26
24
NAP 500
26.1 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 -).
26.2 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.
26.3 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.
26 Installation and Operation
The NAP 500 and NAP 500PS 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 NAP 500PS 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.