FYI, here's an iFi survey on a amp they are thinking about developing suited for specific cans. I couple are indicated, go ahead and vote. I am assuming it's a Drop collab given the cans. https://us5.list-manage.com/survey?u=6607f3ac6b09465840419622f&id=9286873bdb I voted for the Fostex TR-XX0 because of the biodyna drivers. I wished there was a Fostex closed planar on the list, or even the HE5XX. Does anyone even know when the last time the Fostex TR-XX0 went on sale?