I have a similar experience. I got the 80 ohm DT 770 because everyone said it didn't need an amp, but then I was reaching 100% volume on my phone and laptop and still wanted more volume. I used my amp and it made a surprising difference, the sound quality improved, soundstage and imaging improved, bass sounded much better and wasn't weak anymore. I didn't expect it to make this much of a difference. The Fiio will be good enough to power these.