I just got the Fiio E11 that I'm using with my Iphone 4S and the L9 line out. I am using these with my Shure E4c.
Well there are two issues:
1) there is a very small hiss when I turn on the E11. It is constant and does not increase when I increase the volume.
2) There is some sort of interference every now and then. Depending on how the E11 is positioned by the Iphone someimes when I select things on the screen I get this weird electronic beep type sound.
Are these normal things? I have yet to try them with my Grado 225s...but we'll see once I get the mini adapter.