Hi guys! I'm looking for some help in narrowing down the field of headphones to try. I recently bought a new Mapletree Audio Designs Ear+ Super headphone amp. This one is an evolution of the old Ear+ since it has EL84 output tubes (cathode follower), but uses a single chassis with solid state rectification (with Black Gate caps). It has a pair of 5751/12AX7 input tubes, and jacks for low or high impedence phones. It should have plenty of power for most of the dynamic phones out there. My primary source is a Modwright Transporter playing FLAC files, and Hi-Rez downloads. I'm told that MAD amps are a great match with Grado's, but my limited experience with Grado's has not been good. First, all of the ones I've tried have been damned uncomfortable. Second, they seem to be too forward for me, in-your-face sound, which can be exciting, but wears me out. My current phones are a set of Senn HD580's that have been upgraded to HD600's with drivers, grilles, Jena Labs cables. These are all-around decent phones -- not wonderful --- and comfortable for me. I'm looking for something to complement them, not replace them. On the other hand, I lean towards mellower but clear, rather than sharper etched presentations. Other than a few Grados, I've only heard the 701/702's and I didn't really like them, nor are they a good match for my tube amp. Music tastes are about 50% classical music (Bach/Beethoven/Brahms/Shubert/etc. -- chamber music, symphonic, piano concertos/sonatas and the like) and 50% a mix of folkie, world, fusion, aldult-alternative, alt-country, and female vocalists (Vienna Teng/Heather Nova/Norah Jones etc.) If I could afford them, I'd probably go for the Beyerdynamic Tesla T-1's, but I'm probably limited to around $500-600 for headphones. I don't mind buying used if good condition. I've been lurking around here for the past year soaking up impressions, but now actively looking for help for this decision. What are the best headphone choices for this amp? Thanks in advance for your advice!