Designed for commercial and industrial use, the CSMA 280 Commercial Series Mixer/Amplifier from JBL is a mixer/amplifier with eight mixer-channel inputs and two output channels. It's capable of reaching 80W of peak power with 10W per channel. The unit's front panel sports volume controls for each channel, as well as two master volume adjustment knobs, two sets of bass and treble controls, and a power switch. The volume controls are illuminated so they can be seen and operated in darkened environments.
The amplifier, capable of driving both eight and four Ohm loads, can be used with 70V and 100V distributed audio systems without the need for a separate transformer. On its back panel you'll find euroblock connections for mic/line inputs, as well as unbalanced RCA inputs, speaker connections, dip switches for input routing, and more. The unit is also equipped with two RJ45 connectors for use with JBL CSR-V in-wall volume controls (available separately).
This Commercial Series mixer/amplifier boasts such features as voice activating ducking (useful for paging over background music), priority muting for channels one and five, and a sleep mode which automatically powers down the unit when no audible signal has been received for longer than 30 minutes. Also, with two auxiliary outputs, you may connect to an additional amplifier, though the master volume and tone controls will have no bearing on the resulting signal.
Channel Modes
8 inputs with 2 outputs of 80W of power.
Controls
Independent Bass and Treble controls for each output channel.
Input level and output volume controls.
Hi-Z Switch
The Hi-Z switch will switch in the built-in output transformer allowing the unit to drive 70V or 100V speaker systems directly when connected to the appropriate output terminals.
Phantom Power
Phantom power (27 V) can be applied to all mic inputs by turning on Phantom Power within the dip switches.
VOX Function
Voice activated ducking is available on input channel 1 and channel 5. The audio input level required to activate ducking is set using the trim pot on the rear panel. Adjusting in the counter-clockwise direction will reduce that level, while the full clockwise setting will disable the VOX function.
Priority Muting
Channels one and five may be used as priority channels, muting all other channels when pins 4 and 5 are shorted using a switch closure. If the amplifier has entered sleep mode due to inactivity, invoking priority will also bring the unit out of sleep and ready for transmitting an announcement.
Remote Volume Control
Remote volume control can be implemented using a CSR-V controller connected via an Ethernet cable to the RJ45 connector on the back panel.
Sleep Mode
This unit is designed to go into sleep mode after approximately 30 minutes operating with no signal at any of the inputs. Return of signal (-40 dBu or 7.75mVRMS) to any input will wake the unit. Also, a switch closure across the priority input pins will return the unit to normal operating mode.
AUX output
An auxiliary output that you may connect to additional amplifiers is available. The audio signal is the mix of the input channels. Note that the master volume control and tone controls will have no effect on the aux output signal.
Manufacturing
Crown's DriveCore technology
HARMAN's GreenEdge environmental standards
Certifications and Approvals
Lead-free RoHS standards, utilizing recycled metals, and using an energy-saving powder coat process
Energy Star certified
