So, I have my new DT 990's plugged into the E10K. The E10k is meant for 16-150ohm's according to Fiio. However. I would like to know how much the headphones would actually be able to handle from the Fiio E10K, would I be able to flip it to high-impedance mode and crank it to 6-7 without...

Hello!   I am fairly new to the "Higher-End" segment of audio. And while I never owner a very good pair of headphones before, I've always enjoyed soundquality. A few days ago, I decided to go buy a pair of Beyerdynamic DT 990 PRO 250ohm with a Fiio E10K DAC/AMP landing on monday.   However...