Introduction   The OPPO PM-3 is my first delve into both OPPO's headphones, and planar magnetic headphones in general. Being fairly new to the hi-fi audio crowd, the $400 I forked over for these cans are the most I've ever spent on a pair of headphones, and I did not do it lightly. My wallet is still a little on the thin side, but I am happy to report that these headphones well warrant their price, and they are really are great.   Packaging, Accessories, Etc.   The PM-3 comes in a stylish dark grey/black box that has a sort of grain feel to it...