Ah! I remember seeing those.
I really want to underscore how much I think people underestimate how much power it takes to drive the MDs. I spent a couple weeks trying to drive them off my MacBook Pro, added in an inexpensive HeadRoom amp and kept thinking they just didn't live up to the hype. When demoing them for my parents, both audiophiles, they had significant issues with them. Finally I plugged them into my Denon speaker pre-amp's headphone amp and... AHHHH! THAT's what people are talking about. Happen to have an old Rotel pre-amp in the basement that's working as quite a nice dedicated amp for headphone listening now...
Those headroom amps really don't quite give the power to more modern headphone drivers.