The Audio2000'S AKJ7046 digital key & echo mixing amplifier is one of the most advanced karaoke equipment featuring innovative design and user-friendly functions. Incorporated with an embedded digital signal processor (DSP), the AKJ7046 features digital controls with digital/numerical V.F.D. display, microphone echo function, music key control and microphone key control. The AKJ7046 features three microphone inputs and four music source inputs, four music sources, a master volume control knob to control the overall sound level, and individual microphone controls. The AKJ7046 further features a key control function, an echo control function and a voice canceling function for karaoke multiplex discs only. A true 150W + 150W acoustic energy delivery power from the AKJ7046 is carefully engineered to present a high-fidelity direct sound field in a small-room acoustic environment, in a large-room acoustic environment, or in a open performance field. In addition, four audio input terminals and three video input terminals enable users to operate up to four audio/video equipment simultaneously. Two video output jacks allow the users to use two TV's or monitors at the same time. A sub-woofer output is provided for connecting the self-powered subwoofer to the AKJ7046. The extraordinary features of quality key control with extremely low key-shift distortion, clear/transparent echo sound, versatile performances and function, and rugged/delicate appearance make the AKJ7046 professional karaoke mixer an outstanding value in any critical karaoke or DJ application.