Powering from a 36 V supply this circuit has a power output of 16 W in 4 ohm loads. With 40 V and an 8 load power output is 13.8 W. Current drain is 870 mA in the first case and 600 mA in the second case. The integrated circuit must be mounted on a large heatsink.
16 W Audio Amplifier Using the TDA1520
