Recently, my SoundMagic E10 Headphones died. Having read many great thinks about Jaben i decided to buy a new pair there, feeling adventurous i picked the Hippo Pro One (single Balance Armature). Beside sounding great in my opinion, the first thing i noticed was a permanent hiss when no music is playing (i have a cowon iaudio 9). I tried other sources and in some the hiss was barely audible, in some other much worse. So i started reading up on the issue and found out that this is common (?) on most IEM with low impedance.
Nevertheless my first question is: Is there any way the hiss comes from a somewhat defective IEM and not from the source?
Beside this, I would like to know in which relation input- and output impedance on source and IEM would have to be to not produce any hiss.
My last question would be if there is anything I can do against the hiss in combination with the iaudio without spending a lot of money on extra-equipment?
Thanks in advance!