Avoid DFR, not worth the price or the hype. If specifically looking to drive dt770, any decent portable dac/amp will do like, Schiit Fulla, ifi Nano, or some DAP .
After reading a lot of articles and comments here, I think I will skip the DFR.
between ifi hip dac and fiio q1 which one do you think is better in terms of sound.
Also, I dont understand what channel imbalance if very clearly.