The CPS4.5 is an four-channel amplifier from Electro-Voice featuring groundbreaking Class-D technology for maximum amp efficiency and minimized heat dissipation in 19-inch racks. Each channel individually provides transformer-less, switchable output characteristics, which enable specific channels to achieve maximum performance.? Power into 2 Ohms, 4 Ohms, 70V or 100V lines are all possible, and no transformer is required.? In Hi-Z operation (70V or 100V), a 50 Hz high-pass filter provides protection against loudspeaker transformer saturation.? Additionally, amplifier channels can be bridged in pairs for double output power.