A blast from the past and history lesson. Decades before the ortho craze reignited with the HiFiMan, Audeze, and Dan Clark Audio a bit later, there were orthodynamic headphones from the 70s. These two headphones in particular were modded by @rhythmdevils, who has recently arisen.* One thing to keep in mind is that they do not sound good in stock form. Take a look at the driver diaphragm. Sure it's not "nano" meter scale material (and that's probably a good thing when it comes to durability); however, take a look at how fine the traces are! That's Japanese manufacturing at its best. (Fostex was the OEM). * We think he might be the star-child who can only wake on occasions when humans reduce their levels of conspicuous consumption, which is the current situation right now because of CV-19.