Like with all good recipes all the ingredients are essential- as with memorable meals. The right people, the right atmosphere, all play a part. It is not so much about what is most important as about what has been distinquished as having played a valuable part in the whole. it comes from experience, and is as individual as experience is. I am inclined to say it is the source-cd player, turntable, tuner, etc. But, in fact, the most important change occurred in my system with the introduction a relatively inexpensive pair of interconnects.This made sense of the rest.