Constant voltage audio systems are commonly used in installations where audio information needs to be distributed over long and varied distances to many different points of load with high total power delivery. These systems are widely used in commercial building installations for public announcement (PA) or for fire safety and building security notifications by specific zone. This application note describes the operation of constant voltage audio systems and derives the equations needed to determine overall system efficiency. Advantages of integrated power amplifiers, such as the TPA3255, compared to traditional discrete amplifier implementations are discussed. An example system was built using the TPA3255 and measurements were taken with different audio transformers to show the impact that different transformer parameters have on overall system efficiency.