This is the FiiO E3 portable headphone amplifier.
I got it at Jaben a few days ago. The price was, shall we say, negligible?
I connected it to my player with my ATH-CKM50s, since the guy at the shop told me that using it with phones fitted with two or more armatures would blow the crossfeeding and basically conk the phones out.
The result? Tighter bass, tamer highs. Very well worth for the money. If you’re using a iPod or something that has an otherwise poor sound quality, you might want to consider investing in this little piece of technology. You can make your way up from there. This is about the smallest portable amplifer you can get, and with its rockbottom price, there should be no harm in giving it a try. You don’t have much to lose anyway. The amount you would be paying for it roughly equates to that of an extremely cheap pair of earphones.