Features

8-Channel/4-Zone Amplifier: The Russound D850 digital multichannel amplifier offers the features custom installation professionals demand while offering a lighter weight, smaller chassis and more efficient Class D power. The feature-rich design of the D850 is ideal for the demands of distributed audio systems and is also compatible with our Russound volume controls. The D850's eight channels are arranged in stereo pairs to provide discreet amplification and custom configurations for each of four zones.

System Configuration: The Russound D850 can be configured as the main amplifier for an audio distribution system or home theater system.

• Distributed Audio: 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.
• Home Theater Application: The D-Series amp is even up to the rigorous demands of home theater applications, easily transforming into a powerful 160 watt x 4 channel amplifier (in bridged mode). You can also choose to individually un-bridge pairs for lower power applications.

Bridged Mode: Each pair of channels is bridgeable (independently), increasing the power output to a single speaker to 160 watts into an 8Ω load.

Ultra-Low Distortion: Ultra-low distortion output (relatively unheard of in other multi-zone amplifiers) allows for clean, undistorted audio even at high listening volumes.

Auto Sensing Zone Inputs w/ Independent Control: Each zone of the amplifier features a stereo RCA input. These line-level inputs are auto-sensing and will activate when an audio signal from a source is present. Each Zone input offers independent gain control for the left and right RCA channel. When used in Bridged Mode, only the left gain is used.

Bus Input & Output: The bus line input is a stereo RCA input that can be used to connect a single source to multiple zones. The bus line output is a stereo RCA output that allows passive passthrough of the Bus Input and can be used to daisy chain the source to other amplifiers in the system.

Speaker Outputs: The Russound D850 multichannel amplifier is fitted with phoenix-style speaker connectors. The minimum speaker impedance is 4Ω for Stereo Mode and 8Ω for Bridge Mode.

Trigger Inputs/Outputs: The Russound multiroom amplifier features Zone 12V trigger inputs/outputs (3.5mm) and Bus 12V trigger inputs/outputs (3.5mm) for added convenience.

• Zone 12V Triggers: The Zone 12V Trigger In is used to activate a specific zone. The Zone Trigger Out can be used to trigger other 12V devices. The delay and audio sensing are bypassed when the 12V Zone Trigger Input is used.
• Bus 12V Triggers: The Bus 12VDC Trigger In is used to activate all zones that are using the Bus Input and disables other zone triggers or signal sensing on those zones when it is used. If the Bus Trigger In has 12V applied to it, only the 12V Bus Trigger Out will have 12V and the Zone Trigger Outputs will not.

Zero Hum: Advanced triggering options allow the amps to operate on demand. Apart from the obvious energy efficiency, there is no amplifier hum on your speakers when the system isn't in use.

Zone Indicator LEDs: The four LEDs on the unit's front-panel correspond to the D850's four stereo zone amplifiers. The LEDs will illuminate blue when the amplifier power is on and a zone is active. The LEDs do not illuminate when a zone is off.

Protection Circuitry: A robust protection circuit provides efficient, safe and reliable operation under extreme conditions and protects each amplifier output channel. Russound's resilient protection circuit maintains safe and dependable operation in maximum performance conditions.

• Thermal Protection: The 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 amplifier.
• Short Circuit Protection: The Russound amplifier is also designed with special circuitry to safeguard the amplifier under a short-circuit condition. A faulty speaker can also cause a short circuit condition. The Zone LED will blink rapidly between Red and Blue when the Zone is in short circuit protection.

Auto Standby: The amplifier will go into Standby mode when audio signal or trigger is not present, and after the minimum delay time has timed out. The amplifier consumes 0.5 Watt or less current while in standby power mode. Standby delay can be adjusted to either 5 seconds, 5 minutes, or 10 minutes by using the DIP switches on the rear panel. This delay is selectable per zone. When an audio signal is not present, the amplifier will automatically go into standby mode after the preset period of time.

Rack Mountable: The multichannel power amplifier includes a set of rack ears for rack mounting applications. The amplifier will take two rack spaces with the feet removed.

Optional Volume Controls: The  D850 amplifier has been tested to work with all Russound autoformer-based volume controls (sold separately).