The JBL® CSMA series of Mixer-Amplifiers are a professional tool with a sleek industrial look that is designed and built for commercial sound applications. Utilizing Crown's DriveCore technology enables significantly reduced size and weight - all mixer/amps are highly efficient, fanless and just 1U rack space high. There are both single channel and two channel models with four or eight mixer channels, respectively.The CSMA mixer/amps offer unmatched ease of use, with a clean, front panel featuring only volume controls for each channel, master volume adjustment, adjustable bass and treble controls and a power switch. All the volume controls are surrounded by an illuminated ring, making them easy to see and operate in darkened environments. The amplifier can drive 8 ohm and 4 ohm loads and can be used with 70V and 100V distributed audio systems without the need for a separate transformer. In addition to balanced mic/line inputs, unbalanced RCA inputs and speaker connections, all units include RJ45 connectors for use with JBL CSR-V in-wall volume controls. All models feature a universal power supply which enables the ability to accept AC voltages from 100 to 240 VAC, 50/60Hz.JBL Commercial mixer/amps are manufactured under HARMAN's GreenEdge™ environmental initiative, conforming to lead-free RoHS standards and utilizing recycled copper, aluminum and steel, an energy-saving powder coat finishing process and other environmentally-conscious manufacturing processes. Their highly efficient DriveCore design reduces power consumption and yields much more efficient operation - up to 80 percent more efficient than previous designs. All models carry a 3-year no-fault transferable warranty.