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Overview: The Russound R850MC is a 4-zone/8-channel power
amplifier ideal for use as the main amplifier in home theater and distributed
audio systems. The 8 channels are arranged in pairs to provide amplification
for four stereo zones. The R850MC provides an array of useful features such as auto-sensing line inputs, bridged mono operation, independent zone triggering,
bus inputs and multiple speaker outputs per zone to meet a wide variety of
applications and configurations.
8-Channel Power Amplifier: The R850MC is rated at 50 watts per
channel into 8 ohms and 80 watts per channel into 4 ohms (single zone driven). With a zone's mode
switch set in the Bridge Mono position, both channels in the zone are combined
for a mono output of 140 watts into an 8-ohm load. All of this power is supplied
by two high-output toroidal transformers. Each amplifier output channel
includes robust protection circuitry for safety and reliability under extreme
System Configuration: The Russound R850MC can be configured as the
main amplifier for an audio distribution system or home theater system.
- Audio Distribution 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 power zone.
- Home Theater System: When the R850MC 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 zone can be used for the surround
Bridged Operation: When the amplifier is in Bridged mode operation,
both the left and right channels are combined for a higher power mono output.
For bridged amplifier operation, connect an 8-ohm minimum load to the Speaker B
outputs and the line level outputs from your source to the left line level
inputs of this amplifier.
Zone Indicator LEDs: The four LEDs on the unit's front-panel correspond
to the R850MC's four stereo zone amplifiers. The LEDs will illuminate red when
the amplifier power is on and a zone is in standby. The LEDs will illuminate
green when a zone is active.
Controls: All controls of the R850MC are found on the unit's
- Power Switch: Turns the amplifier on or off. This switch does not
disconnect the main power feed from the amplifier; this requires that the
power cord be unplugged from the outlet.
- Gain Controls: Left and Right gain controls independently adjust
the sound level for each channel. When used in the bridged mode only the
Left control is used.
- Line/Bus Switch: Sets the zone input to the Line audio input or
the Bus input.
- Delay Time Dial: Muting delay can be adjusted from 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.
- Stereo/Bridge Mono Switch: Sets each zone amplifier for stereo or
bridged mono operation.
Connections: All connections are found on the rear-panel of the
Russound 4-zone/8-channel power amplifier.
- Bus Input/Output: The stereo RCA bus line input is an optional
input that can be used to connect a single source to multiple zones. The
stereo RCA bus line output is a passive pass-through of the bus input and
can be used to daisy chaining the source to other amplifiers in your system.
- Line Input: The stereo RCA 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.
- 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.
- 12VDC Trigger In/Out: The 3.5m 12V Trigger Input is used to
activate a zone. The 3.5mm 12V Trigger Output 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.
- Fuse Receptacle: Holds a replaceable fuse for AC power input
connections. Fuse rating is T10AL 250V.
- AC Input: The AC voltage input is 120VAC at 60Hz. This receptacle
accepts a 3-prong IEC 20 type connector. A detachable 6 foot, 3-terminal
power cord is included.
Thermal Protection: The Russound 4-zone/8-channel power
amplifier is designed with special circuitry 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
Protection Circuitry: This Russound multi-zone/multi-channel
power amplifier is designed with special circuitry to safeguard the amplifier
under a short-circuit condition. A faulty speaker can also cause a short circuit
condition. The front panel LED illuminates orange when the amplifier is in short
Rack Mounting: The R850MC amplifier can be rack mounted using the
included rack-mount ears and hardware. The amplifier will take 3 rack spaces
with the feet removed.
- Single Zone Maximum Output Power: 0.1%THD+N; f = 1kHz
- 50W per channel, 2 channels at 8 ohms
- 80W per channel, 2 channels at 4 ohms
- 140W at 8 ohms, 2 channels bridged
- All Zones Continuous Output Power: 0.1%THD+N; f = 1kHz
- 35W per channel, 8 channels at 8 ohms
- 50W per channel, 8 channels at 4 ohms
- 100W at 8 ohms, each zone bridged
- THD+N: <0.05% 8 ohms 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: 47k ohms Line Input
- Voltage Gain: 32 dB
- Delay Time: 0.5 to 4.5 minutes
- Input Trigger: 12VDC 10 kohms
- Output Trigger: 12VDC 100mA
- Power Requirements: 120VAC 60Hz 5A
- Dimensions: 16.9375" W x 5.824" H x 18.1875" D
- Weight: 38.1 lbs