Ac Power And Control; Ac Power Input; Power Switch And Indicator; Turn On/Off Mode Selector - Rotel RMB-1048 Owner's Manual

RMB-1048 Eight Channel Power Amplifier

AC Power and Control

AC Power Input

The RMB-1048 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 RMB-1048.
Be sure the Power Switch on the front panel
of the RMB-1048 is turned off. Then, plug one
end of the cord into the AC power connector
on the back panel of the amplifier. Plug
the other end into an appropriate AC outlet.
Your RMB-1048 is configured at the factory
for the proper AC line voltage in the country
where you purchased it (USA: 115 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 RMB-1048
to another country, it is possible to config-
ure your amplifier for use on a different
line voltage. Do not attempt to perform this
conversion yourself. Opening the enclosure
of the RMB-1048 exposes you to danger-
ous voltages. Consult a qualified technician
or the Rotel factory service department for
information.
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
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 am-
plifier is turned on. To turn the amplifier off,
push the button again and return it to the out
position.

Turn On/Off Mode Selector

The RMB-1048 can be turned on and off
automatically by using its "12V Trigger" sys-
tem. 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 us-
ing 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 func-
tion. 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
The jack labeled IN is for connecting the 3.5mm
Plug/Cable carrying a +12 volt trigger sig-
nal to turn the amplifier on and off. To use
this feature the adjacent slide switch must be
set in the 12V TRIG position (see previous sec-
tion). This input accepts any control signal (AC
or DC) ranging from 3 volts to 30 volts.
The jack labeled OUT is for connecting an-
other 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.
6

Protection Indicators

Thermal and protection circuits protect the am-
plifier against potential damage in the event
of extreme or faulty operating conditions.
Unlike many designs, the RMB-1048's protec-
tion circuit is independent of the audio sig-
nal 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 RMB-1048 includes overcurrent
protection which operates only when load im-
pedances drop too low. This protection is in-
dependent for each of the four pair of chan-
nels with separate front panel PROTECTION
LEDS for each.
Should a faulty condition arise, the amplifier
will stop playing and one or more of the PRO-
TECTION LEDS on the front panel will light.
If this happens, turn the amplifier off, let it cool
down for several minutes, and attempt to iden-
tify and correct the problem. When you turn
the amplifier back on, the protection circuit
will automatically reset and the PROTECTION
LEDS 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 protec-
tion circuit to engage.