You are right that this hub comes unpowered although it does have a power socket in case anyone wants to power it.
Unpowered it works with the Dragonfly DAC which the iPhone 5 would otherwise reject as needing too much power.
It won't work with the Dragonfly and my ipad3 although all current iPads worked when I tested them.
It only works for a few seconds with my old Fiio E17.
So my answer is maybe. What is your DAC?
The other option which I know works is the Matrix USB to SPDIF converter. I think it cost me about £40. I ordered from China using eBay and it arrived in about a week. I am sure it's been discussed in this thread. The device looks like an AA battery and works with both iPad and iPhone using ampliflac and Flacplayer.