Now I have the new Beyerdynamic A 200 P found.
This mobile converter, which is built from Astell & Kern and the same Wolfson converter like the iRiver AK 100 used, is the better choice for me at the same price. Its sound is the meridian more than equal to the PC but it is also smart to use the iPhone or any Android.
The Meridian I give because of the limitations only 4 stars.