Wonder what this would sould like with a S:Flo2.. anyway, nice review and pics Warrior, thinking about buying 1 myself with some M2's to try out next month.Fiio E7 Impressions
I tried the combo before but it doesn't turn out well. E7 has a fixed 3dB gain which will clip (distort) with s:flo2's line out. This is due to the really high output of s:flo2's line-out exceeding the maximum output of E7 under the 3dB gain. The only way to use E7 with s:flo2 is to keep the volume really low, which probably isn't a good thing for s:flo2 user. Other players, like iPod and Sansa Fuze, do not have this problem since their line-out isn't quite as strong.
Anyway, it doesn't really matter since I find that s:flo2 headphone-out is almost as good as E7 (when connected to PC). As I said in the review, sub$100 amp probably won't do any good to s:flo2 as its headphone is really good enough to match those amp.
s:flo2 uses the same Wolfson DAC --two of them, actually, for endlessly debatable reasons/perceived benefits-- as the E7. Also, as indicated above, the line-out stage in the s:flo2 already has a high output (because of the OPA2604 opamp) so it's not a "true" line-out stage that would benefit from use of the E7.