Headhones and speakers make the big difference, the rest is small in comparison, unless one got a piece of bad kit. Perhaps some people are hearing things that are not really happening or just don't understand what human percepitve limits are. Our limits of JDD make a lot of this stuff a bit on the silly side. Headphones and loudspeakers produce far more distortion and have issues with FR that one will not find in amps and DACs and that is reality. Of course I'm not forcing anyone to believe, one can think as they wish.