UPDATE: I was wondering if this "popping" noise/jitter is produced by old batches only. Or does it produce on newer batches as well? Alright, this thread was originally started when I had popping sounds for my first FiiO E10. After founding out my E10 was "defective", we made no further attempt to fix it and thus the thread was inactive. As a result, after few weeks of waiting I've just received my second FiiO E10 (replacement for the first one). However, after testing it on different PC/laptops and guess what... I can hear the SAME OLD POPPING SOUND just like the first E10. I really really really don't know what to do now... seriously, this is pissing me off so bad that I want to break this piece of junk. I just can't afford to waste more return shipping fee (Yes, I had to pay both the posting from my end AND their end; if I pay this once again, then the total of shipping fees that I've paid will exceed the value of E10...) and God knows if they are going to give me another new one or not... Someone please tell me that this "popping" noise is normal for E10... please I beg you... This is the description that I used when I first started this thread: Spoiler: Warning: Spoiler! I've recently bought a FiiO E10 DAC for my AKG-K701 and everything has been good except, I can hear popping sound from time to time. At first, I put up with it though right now it's just getting annoying. I'm currently using it on my PC and I've tried different USB slots (3.0 and 2.0) however, the popping sound keeps coming back. The device was also installed successfully so I don't know what's causing this "popping" sound... I don't think my device is defective as the sound itself has no problem. As a result, I'm starting to think if this is a normal behavior? Or is there a way to fix this? Moreover, my headphone has 64 ohm rated impedance so do I need to set the gain to high? (You know, the slider on the amp)? Thank you.