Wow! I had read that combining the Alpen E17 (now discontinued) with the X5 does not do much for the sound. I would have respectfully disagree, at least with the M2 headphones. I find that there is MUCH more sound, and because it has treble and bass adjustments, I can control it better than I can with the X5 EQ (it sux unless you are looking for VERY small adjustments, in which it is great. Plus Fiio gave the EQ a -6dB gain across the board, any time it is active). I really liked the way these new cans sounded before, but I find that now, they sound much better.
For giggles, I tried using the X5+E17 in both combinations (E17 as a DAC, and E17 as amp). I prefer the sound of the X5 overall, so I decided to go with using the E17 as an amp. This paired with the M2s sound great. I am using EQ Off on the X5. I'm using Treble +6 and Bass +2 on the E17. I really do prefer a slight V sound signature with MOST of my music (but not all), which is a lot of metal, or at least hard rock. I am connecting a 3.5mm jack to LO of X5 to Aux in of E17, and using the HP port of the E17 for the M2s....
I have to amend my mini-review a tad bit. When I am at the computer, I wear glasses. The comfort level (or more specifically the time it takes to start getting uncomfortable) is significantly reduced while wearing glasses. There is not a ton of clamping force on these, but they weigh a slight bit more than the M1s (with the electronics), so after a while you will get the same discomfort as if there WERE some clamping force all. Mind you this is coming from someone that has a very small head, and the band only contacts the very top of my head (maybe a bit more than that, but it doesn't hug my head at all), so the majority of the force (weight) is resting on the pads on the side of my head (in this case my glasses, which are starting to hurt the top of my ears).
For giggles, I tried using the X5+E17 in both combinations (E17 as a DAC, and E17 as amp). I prefer the sound of the X5 overall, so I decided to go with using the E17 as an amp. This paired with the M2s sound great. I am using EQ Off on the X5. I'm using Treble +6 and Bass +2 on the E17. I really do prefer a slight V sound signature with MOST of my music (but not all), which is a lot of metal, or at least hard rock. I am connecting a 3.5mm jack to LO of X5 to Aux in of E17, and using the HP port of the E17 for the M2s....
I have to amend my mini-review a tad bit. When I am at the computer, I wear glasses. The comfort level (or more specifically the time it takes to start getting uncomfortable) is significantly reduced while wearing glasses. There is not a ton of clamping force on these, but they weigh a slight bit more than the M1s (with the electronics), so after a while you will get the same discomfort as if there WERE some clamping force all. Mind you this is coming from someone that has a very small head, and the band only contacts the very top of my head (maybe a bit more than that, but it doesn't hug my head at all), so the majority of the force (weight) is resting on the pads on the side of my head (in this case my glasses, which are starting to hurt the top of my ears).