GBNAD 218 THX POWER AMPLIFIER
A NOTE ON INSTALLATIONpeak power levels that may occur in the Obridged�
mode or with low-impedance speakers. At moments
This unit may be installed on any level surface thatwhen the amplifier is producing maximum power,
is strong enough to support its weight. Since its
power transformer generates a significant magneticvoltages of nearly 100V may be present on the
speaker terminals, so the terminals are protected by
hum field, a turntable (especially one with a moving-hinged plastic safety covers.
coil pickup cartridge) should not be located adjacent
To connect loudspeaker cables, first switch off the
to the amplifier nor directly above it.
The heat-sink fins make it awkward to lift the 218amplifierOs power. If you are connecting a pair of
speakers for normal stereo operation, be sure that
THX by grasping the left and right sides. You maythe Bridging switch is set to OFF (STEREO). Raise
find it more practical to place your hands under the
front and rear panels. Much of the amplifierOs weightthe plastic cover to gain access to the
SPEAKERSterminals.
is near the front panel.
CAUTION: The amplifierOs weight must always restFor best stereo imaging, the left and right speakers
should be located at equal distances from your chair.
on its bottom feet. Never put the amp down on itsTo minimize the effect of speaker cables on the
rear panel, with its front panel facing up. Doing so
sound, locate the amplifier near the speakers and use
risks damage to the input/output connectors. short cables to connect the speakers. If your pream-
The amplifier generates a moderate amount ofplifier is located at the opposite end of the room near
heat, requiring internal ventilation. Do not permit theyour chair, you will need a long cable to connect it to
air outlet grille on the top cover to be obstructed bythe power amplifier. All NAD preamplifiers have the
papers or articles of clothing. If you want to locatelow output impedance required to drive long connect-
the amplifier on a carpeted floor, place a board undering cables.
the amp in order to prevent it from sinking into the
carpet, blocking the air inlets on its bottom. Connect the wires from your left-channel speaker
to the (L+) and (L-) terminals in the SPEAKERS
CAUTION: To prevent a fire or shock hazard, dogroup, and connect the wires from the right-channel
not permit liquid or moisture to enter the amplifier. If
speaker to the (R+) and (R-) terminals. In each chan-
liquid is accidentally spilled on it, immediately shut offnel the red terminal is the positive (+) output, and the
the power and unplug the AC power cord. Allow time
black terminal is the negative (-) or Oground� terminal.
for complete evaporation to occur before operatingUse heavy-duty (16-gauge or thicker) stranded
the amplifier again. (If the liquid is anything but water
and/or alcohol, the amplifier should be examined by awire, especially with 4-ohm loudspeakers. Bare wires
can be connected directly to the binding-post termi-
service technician before power is applied to it.) nals. For a longer-lasting and more corrosion-resis-
Do not open the amplifier, or attempt to modify or
tant connection you may purchase speaker cables
repair it yourself. Refer all servicing to a qualifiedwith nickel or gold-plated connectors (pin connectors,
technician. spade lugsfor 230V versions, or banana plugs for
120V versions), or you can install such connectors on
the wires yourself. Connections to each binding post
may be made in several ways, as follows.
(1) Pin connectors. A pin connector is a slim metal
REAR PANEL CONNECTIONS
shaft that is crimped or soldered onto the end of a
1. AC POWER CORD wire. The threaded shaft of each binding post con-
Plug the AC power cord into a live wall socket. Iftains an opening that accepts pin connectors up to
you must use an extension cord, select a heavy-duty
3mm in diameter. Unscrew the red or black plastic
cord of the type used for large electrical appliances.bushing on each terminal to expose the hole in the
Do not connect the amplifierOs power cord to themetal shaft. Insert the pin connector through the
accessory AC outlets on a preamplifier. Such conve-hole, and turn the bushing clockwise until it is tight.
nience outlets are not designed to supply the high
power levels, up to 800 watts, that the 218 THX(2) Spade lugs. Unscrew the colored bushing,
insert the U-shaped spade lug behind the bushing,
requires. If you wish to switch your entire audio sys-and tighten the bushing down on it.
tem on and off at once, plug both the 218 THX and
(3) Bare wires [See Figure 1]. Separate the two
your preamp into a Opower strip� containing severalconductors of the cord, and strip off a half-inch (1 cm)
grounded AC outlets and a high-current on/off switch.
of insulation from each. In each conductor, twist
Voltage conversion. A notice printed on the reartogether the exposed wire strands. Unscrew the red
indicates the AC power-line voltage that the amplifieror black bushing, insert the bare wire through the
requires. However every Model 218 THX amplifier
hole in the metal shaft, and tighten the plastic bush-
has a Ouniversal� power supply that can be modifieding until it grasps the wire securely. Check to be sure
easily for operation in other countries. If you wish to
transport your 218 THX to a nation that employs a dif-that no loose strand of wire is touching the chassis or
an adjacent terminal. (Loose strands can be prevent-
ferent power-line voltage, an authorised NAD dealered by Otinning� the bare wire with melted solder
or service agency can convert it for such use.
before you connect it to the amplifier.)
CAUTION: Safety organizations recommend that
2. SPEAKERS
the speaker terminals of a very powerful amplifier
This amplifier is equipped with special high-currentshould be covered. Potentially dangerous voltages
binding-post speaker terminals to handle the highest
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ACEC
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