I still have it, I'm not positive about the iPod 5s, but it works with my Note 3 + OTG cable.
I heard it run the HD650s in a local shop and to my surprise it sounded awesome to my ears, I didn't have the same impression with the HE400s when I had them with the UHA 6S-II. Is it going to be the same as a desktop amp? No, but it will run them.
Yes it's an amp+dac, check here for the full list of features: http://www.leckertonaudio.com/products/uha760
Let me know...