Adding an amp is not only for impedance purposes.
Just because "you don't need one" doesn't necessarily mean it won't make a difference. Gotta think out of the square some.... You can use portable amplifiers to give headphones tonal changes, more body, weight, enhance detail, tighten up bass, widened soundstage, increase instrument separation, less distortion, the list goes on. There's lots of reasons to add an amp to your set up more than not besides needing more power even for low impedance heaphones. The general thing I see here is people asking if they need amp then members reply with the question "what headphones you using" "Nah they're 32ohms don't need one" is too common without people explaining.
For example: My TF10 (32ohms) sound down right bland coming from my Cowon S9 alone. Thin, lacking soundstage, volume, I find myself pumping the volume up to levels the Cowon can't handle before distortion which leaves me high and dry with no-where to go. Add a Fiio E11 to my set up and all those problems go away, I gain benefits from using it far more than any disadvantages even down to my player consuming less battery power.
I recommend trying a Fiio E6 with your new headphones and decide for yourself. I can almost promise you - you'll see an improvement in the areas I mentioned, it's a matter of trying for yourself to see the differences.
Goodluck.
