My E10 is now starting to do strange things. Often, just moving my headphone jack, I get quite a lot of crackling. Also, when I move the volume pot or even just touch it, I seem to hear all this strange hissing and interference. Even when my computer is left alone not doing anything, I keep hearing some quiet sounds that I can't really describe. It is just starting to sound a bit more like listening to my headphones directly from my PC. It used to be totally quiet with no background hiss at all. What is most strange though is that this problem comes and goes. The other day, it was so bad that if I touched any metal part of the X3, I would hear interference.
The sound quality is still as good as it was though.
What worries me more it what happened with my FiiO X3 the other day. While listening to my X3 at the same time as it being on charge, I just happened to gently contact metal to metal with the E10 and normally, nothing should happen. My X3 got forced off and I heard a loud pop through my headphones. That was either my X3 being sensitive or more likely, my E10 becoming faulty. I will just have to see how I get along with it.
My E10 is about 18 months old now but it is the only FiiO device that I have had big problems with. I have had my E11 for about twice as long and it is much more cheaply made and is covered in dents and yet is still working fine.