For use in professional audio amplifier applications, high current charge pump circuits including charge circuits and dynamic release circuits are connected between respective storage capacitors and the audio power amplifier output. The charge circuits charge their storage capacitors when an output signal swing of the power amplifier is below a corresponding predetermined positive and negative threshold. The dynamic release circuits release power from their charged storage capacitors to dynamically vary the voltage levels of their positive and negative power supply rails in direct relation to the output signal swing of the power amplifier, preferably at unity gain. Multiple positive and negative power supply rails at different voltage levels can be used with cascaded multi-stage dynamic release circuits to maximize system efficiency. The charge and dynamic release circuits can be connected between their storage capacitors and a buffer amplifier which also receives the power amplifier audio input.