GB
mode or with low-impedance loudspeakers. ConnectSOFT CLIPPING circuit gently limits the output wave-
the loudspeakers with heavy-duty (16-gauge or thick-form and minimizes audible distortion when the
er) stranded wire. amplifier is overdriven. We recommend that it be
switched ON when playing music at levels that might
Connections may be made in either of two ways.exceed the amplifierOs power capacity.
[See Figure 2.]
(1) Strip off a half-inch (1 cm) of insulation from
each speaker wire. In each conductor, twist the thin
strands of wire together. Unscrew the knob, insert
the bare wire into the opening at the base of the bind-
ing post, and tighten the knob until it grasps the wireFRONT PANEL
securely. Check to be sure that no loose strand of1. POWER
wire is touching the chassis or an adjacent terminal. Press this button to switch the amplifier on or off. A
(2) Install banana plugs on your speaker wires,green LED above the power button illuminates when
and plug them into the end of each binding post. Thethe power is on.
terminals are separated by 3/4 inch (19mm), so they
will accept dual-banana plugs.
Connect the wires from the left-channel speaker to
the CH 1 + and CH 1 - terminals and the wires from
the right-channel speaker to the CH 2 + and CH 2 -
terminals.
NOTE N Stereo speakers must operate in phase
with each other in order to produce a focused stereo
image and to reinforce rather than cancel each
otherOs output at low frequencies. When connecting
speakers, take care that the red (positive) terminal on
each loudspeaker is connected to the corresponding
red (positive) terminal on the amplifier.
6. BRIDGING
The two amplifiers within the Model 912 can be
Obridged� to form a single amplifier of about three
times the power per channel.
To convert to bridged operation:
(1) Switch the POWER off.
(2) Disconnect any input and output cables.
(3) Set the bridging switch to ON.
(4) Select the cable from the speaker that is to be
driven by the 912. Connect its Opositive� conductor to
the CH 1 + terminal and its Onegative� conductor to
the CH 2 + terminal (i.e. to the two red terminals). DO
NOT connect any wires to the black terminals (CH 1 -
and CH 2 -).
CAUTION: In the bridged mode, wires must be
connected directly from the amplifier to the speakers,
not to a speaker switch, headphone adapter, or any
other device that shares a common ground between
channels.
(5) Connect the signal lead from the source chosen
to be amplified by the bridging amplifier to the input
socket of the CH 1 amplifier.
(6) Turn the POWER on.
NOTE N If you are using two pairs of speakers on
one channel, or if you are in the bridged mode, we
recommend that the speakers have a nominal imped-
ance of 8 or more.
7. SOFT CLIPPING
When an amplifier is driven beyond its specified
power output it normally produces Ohard clipping� of
the signal with harsh distortion and power-supply
buzz as the output transistors saturate. The NAD
NA D
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ACEC
