Blatant clipping is pretty easy to detect... you turn up the volume some more but the sound doesn't really seem to get a lot louder, just more distorted. If you hear that, back off the volume immediately...

I'm not quite sure how to describe the sound of subtle, occasional clipping of the peaks. That's part of the problem

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8