Myself and several from my office bought that big blue dac/amp. When it comes in I'll give my impressions I guess.
Well I got it in this past weekend along with my colleagues. I have to say it's a nice little portable dac/amp. I don't have another portable one to compare it to, but I do have an uber schiit stack and an FX-audio dac-x6 desktop solutions to compare to.
First off, it isn't as powerful as either of my desktop solutions. Volume just doesn't go as loud. The volume nob is also weird because there is no stop points. It spins until you reach max value and if you continue to spin in that direction nothing happens. It starts lowering the volume from where ever you start spinning the other way.
The size is about the size of a pack of cigs. Maybe a tad smaller. It's lightweight and easy to carry so fits the bill of being portable. It charges and takes digit input off the one and only USB port on the back. It will do spdif in/out and 3.5mm in and out as well. It is fairly attractive as well.
As far as sound, it is clear, crisp, great imaging, great soundstage, and warm. Has a bit of extra bass and mid/bass boost going on. So everything sounds lush and warmer than either my schiit stack of the dac-x6 setup which both are very neutral and similar sounding. This actually pairs very well with my more bass anemic cans like the SHP9500. Don't get me wrong, the SHP9500 sound great with my desktop setups, but it just seems slightly better to me with this one. That isn't the same for headphones which have better bass. It just gets overbearing in those cans.
Overall I'm impressed with the $25 shipped this was. Well worth the cost. I hadn't tried the battery life yet so I can't comment on it. The bluetooth sounds great for what it is. It's bluetooth.