Hafler 9130 - Manual (Page 9)

OUTPUTS
All output connections to the amplifier must be performed with the amplifier off!
GAIN
CONTROLS
MONO/
STEREO
SWITCHING
SOFT TURN-
ON/OFF
SYSTEM
THERMAL
PROTECTION
SYSTEM
The left and right audio outputs from the amplifier are via standard 5-way type, 3/4” spacing, binding
posts. Connect these binding posts to the loudspeakers. The amplifier’s binding posts will accept
single or dual banana plugs, spade lugs, pin plugs, or bare wires. If using bare wires, it is recommended
that the ends of the wire be tinned with solder so that no stray strands can cause a short circuit to the
chassis or adjacent terminals.
To ensure proper speaker phasing and frequency response, be sure to connect each respective
amplifier RED (+) terminal to the speaker RED (+) terminal, and the amplifier BLACK (-) terminal to the
speaker BLACK (-) terminal. The polarity symbols (+/-) for Stereo Mode are labelled directly above
the amplifier’s binding posts.
For operation in the Mono Mode, a single loudspeaker should be connected to the two RED binding
posts only. No connection is made to the amplifier’s BLACK binding posts. Connect the speaker’s RED
(+) terminal to the amplifier’s RED terminal labelled (+), and the speaker’s BLACK (-) terminal to the
amplifier’s RED terminal labelled (-). The polarity symbols (+/-) for the Mono Mode are labelled above
the polarity markings for the Stereo Mode.
The 9130 Amplifier is equipped with front panel mounted Gain Controls. These controls may be used
to attenuate the input signal to the amplifier. The maximum clockwise position of these controls applies
the full input signal to the amplifier. Intermediate positions of these controls will partially attenuate the
signal, and the full counter-clockwise position attenuates the input signal completely.
Most applications will dictate that these controls be set to their maximum clockwise position. In
situations of unusually high level signal sources, or for matching levels in multiple amplifier installa-
tions, it may be desirable to use an intermediate position of the Gain Controls. Unless intentionally
introducing different gain levels in the two channels of the amplifier, these controls should normally be
set at the same rotational position.
In the Mono Mode, the Left Gain Control affects the overall gain of the amplifier. The Right Gain Control
has no effect.
The 9130 Amplifier may be operated in the normal two channel Stereo Mode, or may be converted
(bridged) to a higher power, single channel amplifier in the Mono Mode.
Operation of the Stereo/Mono switch must be performed with the amplifier off! Set the Stereo/Mono
Switch in the OUT position for Stereo Mode, or in the IN position for Mono Mode. Mono Mode operation
requires different input and output connections: consult the sections of the manual titled “Inputs” and
“Outputs”.
The 9130 Amplifier is equipped with a Soft Turn-On/Off System that gradually activates the amplifier’s
circuitry to avoid spurious noises as the power supply stabilizes.
At turn-off, this same system rapidly deactivates the amplifier’s circuitry before the power supply begins
to collapse, again eliminating any spurious noises.
The 9130 Amplifier is equipped with a Thermal Protection System that constantly monitors the
temperature of the heatsinks. When the heatsink temperature reaches a pre-determined level, the
amplifier’s circuitry is electronically shut down through the same system that provides the Soft Turn-
On function. When the heatsinks cool to a safe operating temperature, normal operation of the
amplifier resumes.
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