Chris, the devil doesn't have a clue; it's unknown for program material to simultaneously require max power in all channels; and incidentally, clipping isn't necessarily damaging whenever it occurs.

I was looking for a lab test on the 818 to show you, but apparently there isn't one published yet. The closest I found was this test of the 1009, which is a 9-channel unit with essentially the same amplifier as the 818, with the same 135 watt rating.

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Enjoy the music, not the equipment.