Don't worry, it goes back if it doesn't work! Tried to hook up in store today but alas, smoke not available. Thanks again for your help.

Thanks for reply! E17 picked up straight away on my S4 so I'm hopeful for Sero if I end up getting it.

Haven't seen any more chatter at Head-Fi (or anywhere else) about the Sero 7; still working for you via USB? Do you have to use any special apps or settings, or does it just work with the stock music player?   Given the cost (now $129!), the reasonable specs, and SD slot I'm considering...

Two questions: 1. Would a combo card reader/USB OTG dongle work to read music off of SD cards concurrently with digital audio out to DAC on something like the Nexus 7(2013 version)? I have a Fiio E17 on the way and am considering a tablet as source, therefore studying options like so many on...

The old (discontinued) Creative Labs Nomad Jukebox 3 has an Optical line out. Actually, the same plug doubles as an analog line-in (stereo mini). I never used the optical facility since I didn't have an appropriate D/A, but there it sits... in my desk drawer, replaced by an iPod Classic 80g...