NAIM 300 Serie Guia Del Usuario página 13

5.7 Using the NPX 300 power supply
The NPX 300 power supply is an optional system upgrade. If adding the NPX 300 power
supply to the NAC 332, first turn the whole system off. Remove the mains cable from the
NAC 332 – it is not required when the unit is powered by the NPX 300.
Add the NPX 300 to the equipment stand and remove the two link plugs from the NAC 332
rear panel.
Connect the un-banded end of the two Burndy cables to the NPX 300. Connect the two
banded ends to the NAC 332. Ensure all the locking rings are tightened fully. Try to "dress"
the cables so they hang as loosely as possible and without touching the stands or the wall
– this will be easier if they are formed to roughly the required shape before connecting
either end.
Connect the power lead to the NPX 300's power socket and then to mains power. Turn the
rest of the system back on.
Turn the NAC 332 back on by pressing the standby button.
6. Mains power, earthing and more
Use only the mains leads and plugs supplied with your NAC 332, or the upgrade Naim
Power-Line mains cable. Where fused plugs are used, 13-Amp fuses should be fitted. Do
not wire voltage dependent resistors or noise suppressors into mains plugs; they degrade
the mains supply and the sound.
6.1 Earthing
In order to avoid hum loops, the signal ground of the whole system should be connected
to the mains earth in one place. Typically, this is at the primary source. The NAC 332
preamplififer has a ground lift switch. Set this to "Default" if the primary source connects
mains earth to signal ground. If no source connects mains earth to signal ground set it to
the "Ground" position.
6.2 Non-rewirable mains plugs
If a non-rewirable plug is cut from a mains lead (for whatever purpose) the plug MUST be
disposed of in a way to render it totally useless. Considerable shock hazard exists if the
cut-off plug is inserted into a mains outlet.
6.3 Mains circuits and interference
A hi-fi system usually shares a mains power circuit with other household equipment,
some of which can cause distortion that may manifest as mechanical hum from mains
transformers, including the large transformer in your NAC 332.
Transformer hum is not transmitted through the speakers and has no effect on the
performance of the system; however, careful positioning of your Naim system may
reduce it, as may a separate, dedicated mains circuit. Such a circuit (ideally with a 30 or
45-Amp rating) will also generally improve system performance. Only seek advice on the
installation of a separate mains circuit from a qualified electrician.
6.4 Lightning precautions
Your Naim system should be turned off and fully disconnected from mains power when
there is a risk of a lightning strike, to protect from potential damage.
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