[Stancrom]

Thanks for the reply. I've tended to charge the amp by leaving plugged into my laptop's USB port overnight (at least 8 hours, maybe more sometimes), the red cycling light has always become static come morning and I've never disconnected early so I've always presumed that it is fully charged at that point... I have only used the amps so far with a pair of AKG K545s so at 32ohms there shouldn't be much of a burden on battery life.... I might try a longer charge next time and ignore the static red light just to see if that makes a difference. Three separate units performing the same though suggests a common factor rather than pure bad luck. I emailed Fiio the first time and they suggested a poor battery likely. Would have expected that to be rare given Fiio's good rep, but given three consecutive experiences, maybe it's a little more prevalent...I had wondered how much impact on power usage the 16dB gain setting would have (at ~half vol), compared with full vol at 0dB gain, as I do like a fair bit of volume and the 0dB setting is never quite enough with my measly i-product outputs.... Thanks

 

[ClieOS]

Have all three E12 came from the same place? I asked because there is a possibility that if the battery has been exposed to high temperature (over 45 degree Celsius) for a prolong period of time during shipping, it can reduce the battery life. In situation like that, the whole box of E12 might suffer the same fate, which could explain why you keep getting poor battery life from E12 by the same vendor. Of course, I am just guessing here. Very low temperature also has ill effect on battery life as well.

 

[Stancrom]

Good call, could well be the case. They have all been from Amazon UK, (but from two different suppliers...) The latest model has the more up-to-date black/red Fiio packaging - the earlier two, the white 'minimalist' cardboard packaging of the older units, so presume they would be from different shipments from China, but maybe not... Will give it another go with a good long charge and see how it fares. Thanks for your replies. 

 

[ZenocideZ]

  Good call, could well be the case. They have all been from Amazon UK, (but from two different suppliers...) The latest model has the more up-to-date black/red Fiio packaging - the earlier two, the white 'minimalist' cardboard packaging of the older units, so presume they would be from different shipments from China, but maybe not... Will give it another go with a good long charge and see how it fares. Thanks for your replies. 

 
Could you post a photo of the new /black/red package of E12?