I just ordered a set of Beyerdynamic DT990 Pros from Amazon and I am already using an Asus Xonar U7. Do you guys and gals think that the U7 headphone amp will be adequate for 250 ohms?
Probably. You can power the DT990 Pros using an iPod Nano without them sounding too bad, so anything with even a basic amp will work.
I have decided to just use the Asus U7 as a dac and get a dedicated amp, I'm looking for something around $100. So far the Schiit Magni, Fiio E12, and Fiio E09k have caught my eye. I would like something that sounds neutral but with a little warmth.
If you want warmth you'll probably want a tube amp, if you want neutral you'll want a solid state amp. The Schiit Vali would probably work since it appears to be a hybrid tube/solid state headphone amp.
I just ordered the Fiio E07k and E09k, thanks for your help!