Rotel RB-991 Bedienungsanleitung Seite 7

fier sees a 4 ohm load. When driving multiple speakers in parallel,
it is recommended that you select speakers with a nominal imped-
ance of 8 ohms or higher. Speaker impedance ratings are less
than precise. In practice, very few loudspeakers will present any
problems for the RB-991.See your Rotel audio retailer if you have
any questions.
Speaker Wire Selection
Use insulated two-conductor
to the speakers. The size and quality of the wire can have an au-
dible effect on the performance of the system. Standard speaker
wire will work, but can result in lower output or diminished bass
response, particularly over longer distances. In general, heavier
wire will improve the sound. For best performance, you may want
to consider special high-quality speaker cables. Your Rotel audio
retailer can help in the selection of appropriate cables for your
system.
Polarity and Phasing
The polarity — the positive/negative orientation of the connec-
tions — for every speaker and amplifier connection must be con-
sistent so all the speakers will be in phase. If the polarity of one
connection is mistakenly reversed, bass output will be very weak
and stereo imaging degraded. All wire is marked so you can iden-
tify the two conductors. There may be ribs or a stripe on the insu-
lation of one conductor. The wire may have clear insulation with
different color conductors (copper and silver). There may be po-
larity indications printed on the insulation. Identify the positive
and negative conductors and be consistent with every speaker
and amplifier connection.
Connecting the Speakers
The RB-991 has two pairs of color coded binding posts on the
back panel. These connectors accept bare wire, connector lugs,
or dual banana type connectors (except in the European Commu-
nity countries where their use is not permitted).
Route the wire from the RB-991to the speakers. Give yourself
enough slack so you can move the components enough to allow
access to the speaker connectors.
If you are using dual banana plugs, connect them to the wires and
then plug into the backs of the binding posts. The collars of the
binding posts should be screwed in all the way (clockwise).
If you are using terminal lugs, connect them to the wires. If you
are attaching bare wires directly to the binding posts, separate
the wire conductors and strip back the insulation from the end of
each conductor. Be careful
screw (turn counterclockwise) the binding post collars. Place the
connector lug around the binding post shaft, or insert the bundled
wire into the hole in the shaft. Turn the collars clockwise to clamp
the connector lug or wire firmly in place.
Note: Be sure there are no loose wire strands
adjacent wires or connectors.
stranded wire to connect the RB-991
not to cut into the wire strands.
that could touch
Troubleshooting
Most difficulties in audio systems are the result of poor or wrong
connections, or improper control settings. If you encounter prob-
lems, isolate the area of the difficulty, check the control settings,
determine the cause of the fault and make the necessary
changes. If you are unable to get sound from the RB-991,refer to
the suggestions for the following conditions:
Front Panel
No main power to the RB-991.Check the front panel power
switch. Make sure that it is set to the on position. Check AC power
connections at the amplifier and the AC outlet.
Fuse Replacement
If everything checks out correctly and you still cannot get the am-
plifier to turn on, check for a blown fuse. Disconnect the AC from
the wall and remove the fuse holder onthe back panel. If the fuse
is blown, replace with a new fuse and try again.
Note: Make sure that the power cord is disconnected from the
wall before checking or replacing the fuse. Replace only with the
identical size and type fuse (70 amp AGC).
No Sound
If the amp is getting AC power, but is producing no sound, check
the Protection indicator on the front panel. If it is lit, see below. If
not, check all of your connections and control settings on associ-
ated components. Check the input selector switch onthe RB-991
back panel to be sure that its setting matches the type of input
you are using.
Protection Indicator
The front panel indicator lights when the RB-991protection cir-
cuits have shut off the amplifier. Typically, this occurs only when
the ventilation openings are blocked, when there is faulty speaker
wiring, or after a period of extreme use. Turn off the system and
wait for the ampto cool. Then push the front panel power switch
in and out to reset the protection devices. If the problem is not
corrected or reoccurs, there is a probFemwith the system or the
amplifier itself.
Un-
Power Indicator Is Not
Is Lit
English
Lit
3