I’m going to keep this short and sweet. The Fiio E17 is a USB DAC and headphone amplifier. It can also run in standalone mode with its internal batteries. I’ve been using the Fiio E17 daily for the past few months. I do a lot of keyboard programming work away from home, and I often need to use earphones. My Shure SE535s, being they awesome (but sensitive) IEMs they are, are way too noisy when plugged into my MacBook Pro. Not only does the Fiio E17 reduce the noise floor to inaudible, the sound quality is better too.
There isn’t too much more to say about this. The unit itself is well designed in terms of materials and usability. The onboard EQ is very usable, though I don’t use it too often. It has adequate power for my Sennheiser HD650s. If you’re looking for a cheap and portable way to improve your computer’s sound quality, definitely consider the Fiio E17.