I recently bought a Fiio E11 amp to improve the sound quality and boost the volume of my iPhone 4s and Phonak 112 iem's. The problem is that unless I switch the phone to airplane mode (thereby disabling the phone, text and wifi) there is too much interference (gsm, emi or whatever) to make listening pleasurable. I'm surprised Fiio haven't addressed this problem, seeing as it's advertised as being suitable for use with the iPhone. I've emailed them asking for advice but they haven't bothered to reply.
I thought maybe the Fiio lod might be to blame but the amp picks up the interference even with the phone just sitting near it unplugged.
So my question is, if the Fiio is only suitable to use with a hobbled iPhone, does anyone make a portable amp that is completely screened and will let me recieve texts/calls and surf the web while I listen to music. Or is that too much to ask?