Sony 7506. Over the years doing sound and monitors around the country, this is the headphone I see engineers use most often. One other difference between the 7506 and the V6 is that parts for the 7506 can be ordered. SO if you break a hinge, you can just order the hinge, or just the earpad if it wears out, etc. I have had mine for several years and they have been used for literally 100's of shows now and besides the standard wear are as nice as the day I bought them.