Abstract: A sound reinforcement apparatus is provided for combining a number of individually generated audio signals and outputting a collective audio signal representative of the sum of the individual audio signals. The apparatus includes a plurality of volume regulating circuits. Each volume regulating circuit communicates with a microphone which outputs one of the audio signals. Each microphone receives the sound produced by one vocalist or instrumentalist. Each of the volume regulating circuits outputs a modified audio signal having a fixed, predetermined level. A volume control signal is also outputted by each of the volume regulating circuits. The volume control signals are sent to a volume summing circuit which outputs a volume control restoring signal. The audio signals are applied to an audio sum circuit which outputs an audio sum signal.