BEHRINGER ULTRATONE K900FX Ultra-flexible 90-Watt 3-channel PA System / Keyboard Amplifier Powerful 12'' BUGERA woofer and custom-made 1'' driver for ultimate sound reproduction Integrated digital FX processor with 100 awesome presets including reverb, chorus, flanger, delay, pitch shifter and various multi-effects Revolutionary FBQ Feedback Detection System instantly reveals critical frequencies Full 3-channel operation with separate Volume and FX Send per channel