6
GB
Notes on Installation Location
Read and follow all the safety instructions on the
first page of this manual.
To prevent a fire or shock hazard, do not place the
amplifier where it will be exposed to any water or
moisture. If liquid is accidentally gets into the ampli-
fier, immediately unplug the AC power cord. Do not
operate the amplifier again until it has been exam-
ined by a service technician.
The amplifier generates a moderate amount of heat,
requiring ventilation. Do not obstruct the air outlet
grilles on the top or bottom covers. There should be
at least 3 inches (7.5 cm) of clearance above the am-
plifier and 1 inch (2.5 cm) to the sides. Do not place
the amplifier in an enclosed area, such as in a book-
case or in a cabinet, unless it is very well ventilated.
Be sure there is adequate room behind the amplifier
for signal input and speaker output connections. If you
want to locate the amplifier on a carpeted floor, place
a board under it in order to prevent it from sinking into
the carpet, blocking the air inlets on the bottom.
Do not place the amplifier where it will be exposed
to direct sun light for prolonged periods of time.
This unit may be installed on any sturdy, level sur-
face. NOTE: The amplifier’s weight must always rest
on its bottom feet. Never put the amp down on its rear
panel, with its front panel facing up. Doing so risks
damage to the input/output connectors.
The power transformer in the 925 generates a mag-
netic hum field of moderate strength. Turntables (es-
pecially those with a moving-coil pickup cartridge)
should not be located near the amplifier. Magnetic
media, such as audio or video tapes and computer
diskettes, should not be stored near the amplifier.
Rear Panel Connections/Controls
1. AC Line Cord
Plug the AC line cord into a nearby wall outlet that
provides the correct AC power line voltage, as indi-
cated on the back panel of the unit. Do not plug the
amplifier into a convenience outlet on your preamp.
The amplifier requires more power than these outlets
typically can provide.
2. Inputs
Each of the five independent power amplifiers within
the 925THX has its own signal input connector. Be-
fore making any connections to the amplifier, make
sure the POWER is switched OFF.
Connect the signal cables from the preamplifier,
surround sound decoder or other signal source to
these inputs.
3. Input Level Controls
The amplifier is equipped with separate input level
controls for each channel. Before turning on the
925THX for the first time, make sure all level controls
are in their normal full-clockwise position.
Under some circumstances, other settings may be
useful for:
(1). Level-matching – In systems that incorporate
speakers of varying efficiencies, it may be necessary
to reduce the settings of some controls to achieve
proper channel-to-channel balance.
(2). Extended volume-control range – Many stereo
systems have so much voltage gain that the speak-
ers (or your ears) are over-driven at any volume-con-
trol setting higher than 11 or 12 o’clock position of the
volume control. As a result you can use only the lower
half of the volume control’s range, where adjustments
are imprecise and channel-balance errors tend to be
greater. If all input level controls are reduced, you can
turn up your preamplifier’s volume control, making
effective use of most of its range. (Suggestion: adjust
the input level controls so that your preferred maxi-
mum sound levels occur at about 2 or 3 o’clock on
the volume control.)
As an added benefit, this procedure suppresses
any noise produced by the preamp’s high-level cir-
cuitry (e.g. any residual hum or hiss that does not go
away when the Volume is turned down).