This is the circuit diagram of 600W MOSFET power amplifier. The circuit will give you more than 600 Watt audio output for speakers with impedance of 4 Ohm. This high power amplifier circuit uses 6 pieces of N-channel MOSFETs IRFP450 in the output stage alone and will give you about 400Watt power. To make more than 600Watt, then you need to use 12 pieces of N-Channel MOSFETs IRFP450. One of the construction sequence to produce more output power of 900W is using 12 pieces IRFP460 MOSFET.
Below is the 600W MOSFET power amplifier circuit design and the power supply circuit designed for this power amplifier. PCB layout design for the power amplifier and it’s power supply is provided.