Blue = input, green = what the amplifier is trying to get it’s output to look like, and orange = output. Don’t try to put a filter between the orange wire and the load. It probably won’t improve the output a lot and will decrease the efficiency of the amp by creating more high frequency signals in the orange wire. I’ve added an RC network to prevent excessive buildup of high frequency signals by acting as a low resistance path to ground for the high frequency signals diminishing them while leaving the low frequency signals untouched. This amp has an efficiency of at least 95% at full load, and consumes about 5 to 15W without an input signal and/or without a load.
