ROTEL RB-1072 - Manual (Page 7)

7 English
AC Power and Control
AC Power Input 8
The RB-1072 is supplied with the proper AC
power cord. Use only this cord or an exact
equivalent. Do not use an extension cord. A
heavy duty multi-tap power outlet strip may
be used, but only if it is rated to handle the
current demand of the RB-1072.
Be sure the Power Switch on the front panel of
the RB-1072 is turned off. Then, plug one end
of the cord into the AC power connector
8 on
the back panel of the amplifier. Plug the other
end into an appropriate AC outlet.
Your RB-1072 is configured at the factory for the
proper AC line voltage in the country where you
purchased it (USA: 120 volts/60 Hz, Europe:
230 volts/50 Hz). The AC line configuration is
noted on a label on the back panel.
NOTE: Should you move your RB-1072 to
another country, it is possible to configure
your amplifier for use on a different line
voltage. Do not attempt to perform this con-
version yourself. Opening the enclosure of
the RB-1072 exposes you to dangerous volt-
ages. Consult a qualified technician or the
Rotel factory service department for infor-
mation.
If you are going to be away from home for
an extended period of time, it is a sensible
precaution to unplug your amplifier.
Power Switch and
Indicator 12
The Power Switch is located on the front panel.
To turn the amplifier on (or to activate either of
the optional automatic power-on modes), push
the switch in. The LED indicator above the switch
will light, indicating that the amplifier is turned
on. To turn the amplifier off, push the button
again and return it to the out position.
Turn On/Off Mode Selector 6
The RB-1072 can be turned on and off auto-
matically by using its “12V Trigger” system.
The Turn On/Off Mode Selector switch is used
to select which method is used.
• With the switch in the OFF position, the
amplifier is turned on or off manually using
the front panel power switch.
• With the switch in the 12V TRIG. position,
the amplifier is turned on automatically
when a 12 volt trigger signal is applied to
the 3.5mm Jack labeled IN. The front panel
POWER SWITCH overrides this function. It
must be ON for the +12V trigger to work.
Turning the switch OFF cuts power to the
amplifier, regardless of whether or not a
trigger signal is present.
+12V Trigger Input
and Output 7
The jack labeled IN is for connecting the 3.5mm
Plug/Cable carrying a +12 volt trigger signal
to turn the amplifier on and off. To use this
feature the adjacent switch
6 must be set in
the 12V TRIG position (see previous section).
This input accepts any control signal (AC or
DC) ranging from 3 volts to 30 volts.
The jack labeled OUT is for connecting another
3.5mm plug/cable to provide a 12V trigger
signal to other components. The 12V output
signal is available whenever a +12 volt trigger
signal is applied to the IN connector.
Protection Indicator
3
Thermal and protection circuits protect the am-
plifier against potential damage in the event of
extreme or faulty operating conditions. Unlike
many designs, the RB-1072’s protection circuit
is independent of the audio signal and has
no impact on sonic performance. Instead, the
protection circuit monitors the temperature of
the output devices and shuts down the amplifier
if safe limits are exceeded.
In addition, the RB-1072 includes overcurrent
protection which operates only when load
impedances drop too low.
Should a faulty condition arise, the amplifier
will stop playing and the PROTECTION LED
on the front panel will light.
If this happens, turn the amplifier off, let it
cool down for several minutes, and attempt to
identify and correct the problem. When you
turn the amplifier back on, the protection circuit
will automatically reset and the PROTECTION
LED should go out.
In most cases, the protection circuitry activates
because of a fault condition such as shorted
speaker wires, or inadequate ventilation lead-
ing to an overheating condition. In very rare
cases, highly reactive or extremely low imped-
ance speaker loads could cause the protection
circuit to engage.
Input Signal Connections
4
See Figure 2
The RB-1072 has standard unbalanced RCA-
type input connectors, the type used on nearly
all audio equipment. There is an RCA input
for each of the two amplifier channels. These
RCA inputs accept audio signals from pre-
amplifiers or surround sound processors. Use
high quality audio interconnect cables for best
performance.
Speaker Connections
See Figure 2
The RB-1072 has two sets of dual binding post
speaker connection terminals, one set for each
amplifier channel.
Speaker Selection
The nominal impedance of the loudspeaker(s)
connected to each channel of the RB-1072
should be no lower than 4 ohms.
Speaker Wire Selection
Use insulated two-conductor stranded wire to
connect the RB-1072 to the speakers. The size
and quality of the wire can have an audible ef-
fect 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 authorized Rotel dealer
can help in the selection of appropriate cables
for your system.
Polarity and Phasing
The polarity – the positive/negative orientation
of the connections – for every speaker and
amplifier connection must be consistent 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
identify the two conductors. There may be ribs
or a stripe on the insulation of one conductor.
The wire may have clear insulation with dif-
ferent color conductors (copper and silver).
There may be polarity indications printed on
the insulation. Identify the positive and nega-
tive conductors and be consistent with every
speaker and amplifier connection.