Hi guys. I've been a professional lurker here for years. Just about 2 years ago I bought my first pair of decent headphones, the Sony MDR-V6. I still have them and I love them, and learnt more about what I want in a pair of headphones since I got them but I still have much to learn. I recently got a Fiio E07k and I love how different my headphones sound with it, however, I'm wondering which headphones and what price range should I be looking at as a step-up from the MDR-V6 for a beginner to higher quality audio like myself. Something that will be obviously better sounding that what I have. Closed-back, over the ear headphones. I've heard of headphones like the HD-280, the Shure 440 and others but I don't know how much of an increase in sound quality there is from the Sony. Thanks for your help!