I'm looking for a portable amp to bring out the bass on my Etymotic's. I was planning on returning them, but I've read that an amp may help my situation. The only problem is I don't know much about amps and I don't want to spend a large amount of time researching. What would be a good combination with the hf5? With an impedance of only 16 Ω it won't need a great deal of amplification. I plan to take these school everyday and my source of music will primarily be from my android phone. I was looking at the Fiio e6 for $25 on amazon. It seem's like a good deal but at that price the amp seems like it may be bad in quality. Price range ~ $100. Although will go up if there is something considerably better.