If you want to use the headphone on the go, then you could consider only closed cans.....
have you looked at v moda m 80, m100? these cans do not need an amp. V moda phones are stylish.....
You are welcome.
X1 has an impedance of 30 Ohms and sensitivity or efficiency of 100 dB/mW. It can be easily driven by soundcard of laptop or ipod or any mobile device. However, a dac/amp such as, E 07K would improve the sound quality of X1 by providing cleaner signal.
you may want to look this thread, http://www.head-fi.org/t/689313/dac-amp-for-fidelio-x1-ratings-and-recommendations-compilation-thread
The cable has 1/4" male pin at one end and 1/8" male pin at another end. E 07k has 1/8" socket. I guess that you need to find a coiled cable that has 1/8" male pins at both ends.
This hobby is much better than playing shooting games. I am sure that you will love x1.
Found this one in ebay, I do not know about the quality of this cable.