REVIEWER INTRODUCTION First of all, I want to introduce my gear while writing this review. I'm using my AKG K612 PRO headphone with my Fiio X3 2nd Gen dedicated DAP. Currently I don't own any headphone amp but planning to buy an A5. I'm gonna update this review when I do.  I use my lossless archive while writing this review. All files are 16/44, 24/96 and 24/192. All of them are checked with spectrometer software.  FIRST IMPRESSION Out of box, this headphone is great when it comes to packaging as well. It's simple but more than enough...