The prototype delivers watts of power output to an 8Ω load when connected to a ±45VDC power supply. The frequency response is flat from 20Hz to 20KHz with a low THD of % ensuring a faithful reproduction of the audio signal. Project 76 is a high-performance audio power amplifier that uses ADA4700-1 in the input stage. This op-amp combines precision, high-voltage and high-current output capabilities with a wide operating voltage range of ±5V to ±50V. The output stage employs a complementary pair of STD03N and STD03P Darlington transistors, which have very high hFE and temperature compensation diodes for optimal audio quality.