R-Series
R1250MC
6-Zone, 12-Channel
Power Amplifier
User’s Manual
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R1250MC AMPLIFIER
INTRODUCTION
The R1250MC is rated at 50 watts per channel into 8
ohms and 80 watts per channel into 4 ohms. With the
Stereo/Bridge Mono switch in the Bridge mode position,
both channels in the zone are combined fora higher pow-
ered mono output. In bridged mode, the R1250MC pro-
vides 140 watts of power into a single 8-ohm load. All
this power is backed by three high output toroidal trans-
formers. Each amplifier output channel incorporates
robust protection circuitry for safety and reliability under
extreme circumstances.
The Russound R1250MC is a 12-channel power amplifier
and is ideal for use as the main amplifier in home theater
and distributed audio systems. The 12 channels are
arranged in pairs to provide amplification for six stereo
zones. The R1250MC provides an array of useful fea-
tures such as bridge mode operation, independent zone
triggering, bus inputs and multiple speaker outputs per
zone to meet a wide variety of applications and configu-
rations.
FRONT PANEL
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Zone Indicator LEDs: The six LEDs correspond to the six stereo zone amplifiers. The LED will illuminate red
when the amplifier power is on and the zone is in standby. The LED will illuminate green when the zone is active.
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RACK MOUNTING
The R1250MC amplifier can be rack mounted using the included rack-mount ears and hardware to attach the ears to
the amplifier. The amplifier will take 3 rack spaces with the feet removed.
R1250MC Side View
Rack Ear
Screw Holes
Rack Ear
Side View
Rack Ear
Front View
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R1250MC AMPLIFIER
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3
4
5
1
6
1
7
11
10
9
8
4
1
2
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Bus Input/Output: The bus line input is an optional
input that can be used to connect a single source
to multiple zones. The bus line output is a passive
passthrough of the bus input and can be used to
daisy chain the source to other amplifiers in the
system.
Fuse Receptacle: Holds a replaceable fuse for AC
power input connection. Fuse rating for North
America and Europe is T10AL 250V.
AC Input: The AC voltage input for the North
American model is 120VAC at 60Hz (for the
European model, 230VAC at 50Hz). This receptacle
accepts a 3-prong IEC 320 type connector. A
detachable 3-terminal power cord is included.
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Line Input: The line audio input for each zone is a
dedicated sensing input that will activate the zone
when an audio signal from a source is present.
12VDC Trigger In/Out: The 12V Trigger In is
used to activate the zone. The Trigger Out provides
100mA 12V max. This can be used to drive other
12V triggered devices. The delay and audio sensing
are bypassed when the 12V trigger input is used.
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Line/Bus Switch: Sets the zone input to the Line
audio input or the Bus input.
Speaker Outputs: The A and B speaker outputs
are in parallel to the amplifier output. The minimum
speaker impedance for stereo mode operation is 4
ohms for one pair and 8 ohms for two pairs of
speakers. The minimum impedance for bridged
mode operation is 8 ohms for Speaker B only.
Delay Time: Muting delay can be adjusted from
about 0.5 minute to 4.5 minutes. When an audio
signal is not present, the amplifier will automatically
go into standby mode after the preset period of
time. When set to maximum, the amplifier will stay
active and not go into standby.
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Gain Controls: Left and Right gain controls inde-
pendently adjust the sound level for each channel.
When used in the bridged mode only the Left con-
trol is used.
Stereo/Bridge Mono Switch: Sets each zone
amplifier for stereo or bridged mono operation.
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Power Switch: Turns the amplifier on/off. This
switch does not disconnect the main power feed
from the amplifier; this requires that the power cord
be unplugged from the outlet.
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R1250MC AMPLIFIER
BRIDGED OPERATION
When the amplifier is in Bridged mode operation, both
the left and right channels are combined for a higher
power mono output.
Following the Bridge mode markings in red on the back
of the amplifier: Connect the negative lead (-) of the
speaker cable to the R+ terminal. Connect the positive
lead (+) of the speaker cable to the L+ terminal. Set the
Stereo/Bridge Mono switch to Bridge Mono, connect the
Line In feed from a source to the Left Line In connection
and restore power to the amplifier.
For bridged amplifier operation, turn off the power to the
amplifier and connect an 8-ohm minimum load to the
Speaker B output.
RCA Cable from source
Right In
Left In
Line In
L
R
Line In
L
R
Bridg e
In
Bridg e
In
Line In
Bus In
Line In
Bus In
Speak er
Speak er
R+
R+
A
A
R-
L-
R-
L-
L
L
L+
L+
R
R
Ster eo
(-)Negative
(-)Negative
Ster eo
Speak er
Speak er
-
-
R+
R-
R+
R-
B
B
Speaker
cable
Speaker
cable
Bridg e Mono
Bridg e Mono
Stereo mode
4? minimum
impedance
L-
Stereo mode
4? minimum
impedance
L-
L+
+
L+
+
Bridge mode
8? minimum
impedance
Bridge mode
8? minimum
impedance
(+)Positive
(+)Positive
DelayTime
DelayTime
Right Speaker
8 ohm
Left Speaker
8 ohm
Out Trigger In
12V 100mA
Out Trigger In
12V 100mA
Zone 1
2
Zone
THERMAL PROTECTION
PROTECTION CIRCUITRY
All Russound amplifiers are designed with special circuit-
ry to safeguard the amplifier under a thermal overload
condition. Thermal protection mode can only engage
when the unit has been run at high volume for extended
periods of time without adequate ventilation and/or when
speaker impedances are below the minimum levels for
the amplifier. If this fault occurs, turn off the amplifier,
and check that the speaker impedance rating is above
the minimum rating. Also check for adequate ventilation
around the amplifier and make adjustments if necessary.
Once the unit has cooled to safe operating tempera-
tures, the amplifier may be powered back on.
All Russound amplifiers are designed with special circuit-
ry to safeguard the amplifier under a short-circuit condi-
tion. A faulty speaker can also cause a short circuit con-
dition.
The front panel LED illuminates orange when the amplifi-
er is in short circuit protection. If this fault condition
occurs, turn off the amplifier and check speakers for
short circuit conditions when appropriate.
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R1250MC AMPLIFIER
POSSIBLE SYSTEM CONFIGURATION
The R1250MC can be configured as the main amplifier for an audio distribution system or home theater system.
When used with an audio distribution preamp, each zone can independently drive one of several different sources by
using each zone’s individual line audio inputs, or a pair of zones can be bridged to create a higher powered zone.
When the R1250MC is used as a home theater amplifier, three zones can be bridged to provide high power for the
front and center channels and the remaining zones can be used for the surround effects.
CAV6.6
Controller
R1250MC
Amplifier
Bridged
Independent Stereo
Bus Input
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R1250MC AMPLIFIER
SPECIFICATIONS
Single Zone Maximum Output Power: 50W per channel, 2 channels at 8 ohms
(0.1% THD+N; f=1 kHz) 80W per channel, 2 channels at 4 ohms
140W at 8 ohms, 2 channels bridged
All Zones Continuous Output Power: 35W per channel, 12 channels at 8 ohms
50W per channel, 12 channels at 4 ohms
100W at 8 ohms, each zone bridged
THD+N: <0.05% from 20Hz to 20kHz
Signal-to-Noise Ratio: >100dB
Frequency Response: 20Hz to 20KHz +/- 0.3dB
Input Sensitivity: 70mV for 1W at 8 ohms
500mV for 50W at 8 ohms
Input Impedance: 47kohms Line Input
Voltage Gain: 32dB
Delay Time: 0.5 to 4.5 minutes
Input Trigger: 12VDC 10 kohms
Output Trigger: 12VDC 100mA
Power Requirements: North American Model:
120VAC 60Hz 7A
IEC 320 type connector with 3 terminal detachable power cord.
Fuse Rating: T10AL 250V
Power Requirements: European Model:
230VAC 50Hz 4A
IEC 320 type connector with 3 terminal detachable power cord.
Fuse Rating: T10AL 250V
Dimensions: 17" W x 16.5"D x 5.875"H (43 x 42 x 15 cm)
Weight: 48.9lbs. (22.2kg)
WARRANTY
The Russound R1250MC is fully guaranteed for two (2) years from the date of purchase against all defects in materials and work-
manship. During this period Russound will replace any defective parts and correct any defect in workmanship without charge for
either parts or labor. For this warranty to apply, the unit must be installed and used according to its written instructions. If service is
necessary, it must be performed by Russound. The unit must be returned to Russound at the owners expense and with prior written
permission. Accidental damage and shipping damage are not considered defects under the terms of the warranty. Russound
assumes no responsibility for defects resulting from abuse or servicing performed by an agency or person not specifically author-
ized in writing by Russound. Damage to or destruction of components due to improper use voids the warranty. In these cases the
repair will be made at the owners expense. To return for repairs, the unit must be shipped to Russound at the owners expense,
along with a note explaining the nature of the service required. Be sure to pack in a corrugated container with at least 3 inches of
resilient material to protect the unit from damage in transit.
Russound sells products only through authorized Dealers and Distributors to ensure that customers obtain proper support and serv-
ice. Any Russound product purchased from an unauthorized dealer or source, including retailers, mail order sellers and online sellers
will not be honored or serviced under existing Russound warranty policy. Any sale of products by an unauthorized source or other
manner not authorized by Russound shall void the warranty on the applicable product.
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R-Series
R1250MC Power Amplifier
User’s Manual
5 Forbes Rd. Newmarket, NH 03857, USA
Tel 603.659.5170 • Fax 603.659.5388
e-mail: [email protected]
28-1168 04/22/05
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