[pj-bs]

Currently I use AKG K121 with a Fiio E10 and I'm thinking about getting a new headphones, maybe K701, Beyer DT660, ATH-AD900X.... 
 
Any idea about what would be best headphone option with Fiio E10 and FLAC files?

 

[cel4145]

I'm not familiar with the K121 sound, but perhaps someone else is. What would you like to improve on vs. your K121s?

Also, do you have a DAC/amp? What are you hooking your headphones up to?