SURGE 5004 is a four channel power amplifier which originates from a class H circuit design with a toroidal transformer. The force cooling fans help maintain the temperature of the vitals inside the amplifier while use. The LCD display helps you monitor the temperature, fan speed, input EQ, Operation mode and channel gain & output & output level, making your operating experience smooth and seamless. This amplifier is ready to rock your line arrays and tops with unmatched reliability and performance.