Well, I was dead wrong about the Fostex T50RP not needing more power. They will play to an ok volume without a better amp, but they sound much better when given more power. At work I'm using the Aune X1S and I have to crank it pretty high. At home I'm using the Schiit Modi 2 Uber, and the Schiit Magni 2 Uber. The Magni 2 Uber has a gain switch, and the high setting is more than equal to the task.
Now I need to re-rip most of my CD collection. Too many ripped at too low a bit rate.