CS® 4000 Power Amplifier The CS 4000 power amplifier is designed to provide years of reliable, flawless operation under rigorous use. This amplifier offers the sonic superiority and unsurpassed reliability for which Peavey is famous, while remaining surprisingly compact. Advanced technology and extensive protection circuitry allow operation with greater efficiency into difficult loads and power conditions. The DDT (Distortion Detection Technique) circuitry ensures trouble-free operation into loads as low as 2 ohms. DDT protects drivers and ensures that sonic integrity is maintained, even in extreme overload conditions. The CS's high-efficiency design uses multi-rail class-H technology to produce high output power while reducing losses. Massive heat-sinks and a high volume cooling fan maintains a lower overall operating temperature, resulting in longer output transistor life.