Followup regarding my hum problems with the E5 first reported in this post (see there for details). I ordered a new unit from head-direct. It does not have the hum problem, so it was definitely a bad unit (how rare we don't know, I think kpsalm was the only other forum member to notice/report...

Quote: Originally Posted by sivakrdy Thats good news. what are the specifications - (output voltage etc) my E5 is in shipping. will purchase an adapter by the time it comes home. As ClieOS said, any good A/C or 12V -> USB converter is fine. The voltage/etc. are the same on all. A...

Quote: Originally Posted by ClieOS Done with the third and yet to encounter any humming, I think i'll stop here and skip the last one. Thanks for taking the time to do the tests!

Quote: Originally Posted by ClieOS If you suspect a defect, I would suggest return it for a new one. I certainly suspect a defect, but was trying to determine whether this was a sample defect vs. a universal problem with the E5's. Or, maybe a bad batch. And, if it's a common...

Quote: Originally Posted by dfkt Shouldn't "normal" hum be 60Hz for American AC? You are absolutely correct. My bad. Confused voltage numbers with frequency. I'll edit my posts.

Quote: Originally Posted by FiiO sorry for the inconveniency of the problem! the hum noise is cause by the power source, if the USB power source is clean enought , it will have not such noise! and E5 have not enough space to place a filter ciruit inside, it needs a bigger capacitor...

Quote: Originally Posted by Kpalsm ... Yes, I have the same problem, I would guess it's an inherent problem with the E5 itself. Fine when it's charging, but not when charged and still plugged in. Loud humming/buzzing sound. I like to plug my Sansa+E5 into my sound card's line in and...

I see several people have recently received their E5's. Any of you have problems with a hum when you are using it when it is fully charged and plugged into the charging source? See my previous posting for the details. Only one person responded, and they were still waiting for theirs to...

I just bought a Fiio E5 - it works fine while it is charging or disconnected from the charging power source - no significant noise, and it drives my headphones quite well. But, when the E5 is fully charged and connected to the power source, the output has a very noticeable 140Hz hum (I...