Incredible little piece of equipment and quite a step up from the FiiO E6. When I opened the package I was surprised by its build quality and size. It is smaller than I thought it would be and much more realistic in terms of weight than I imagined. This little guy really opens up any headphone you throw at it. I'm using it with my Audio-Technica ATH-M50s right now and occasionally use it with my Grados. Would highly recommend this to anyone looking for a reasonably priced, portable amp/dac.