The tiny Fiio E5 headphone amplifier, clearly inspired by Apples iPod Shuffle MP3 player, will help to give the volume from your favorite digital audio player a good boost.
The 26 gram light amplifier measures 44 x 38 x 12.2mm. It’s powered by a built-in USB rechargeable 200mAh lithium battery that allows for up to 20 hours of use.
According to GenerationMP3, the Fiio E5 headphone amplifier will retail for under $20.
I thinkk mcintosh is a good alternative when it comes to amplifiers.