I've had the DX100 for approximately a month now and believe I have reached a point where I can confidently share a few impressions. It seems to me headphones are better driven by the DX than iems. With the ES5, Miracles and UERM the sound is weighty, dynamic but at times minus the finesse, polish and focus I find, in varying degrees, with any of my three portable amps (Stepdance, SR71A, Pico Slim). I do, however, find that using the DX100 as a DAC is nearly worth the price of admission. Particularly into the Stepdance and out into the Miracles the synergy is mesmerizing. The Miracles are a languid, stubborn pair of customs, and are reluctant to overtax themselves, but this combination has awoken them and the chains removed (especially in treble shimmer and sparkle). Compared to the CLAS, which has been my go-to portable setup for some time now, I cannot say the DX100 is a blatant improvement with iems. The CLAS is more analog, with a wider and deeper soundstage, but not as full-sounding or dynamic. Detail retrieval is similar on first glance, but more back to back comparisons are needed. I sometimes find myself wondering whether driving iem's is optimal on the DX. The sound is, at times, too aggressive, too forward and uni-directional (as though everything were rushed forward). At other times, however, I experience that mysterious elation, that perfect cohesion of sound quality and mindset, and I cannot recall having such a quanity of those moments with the CLAS.
Today I plugged in my newly arrived ATH-AD2000 and quickly concluded the amp in the DX100 was more adept (more insistent, focused) than the Stepdance. It was a short session, but nonetheless revealing. The Stepdance (on low gain) seemed unsure of what to do with the load and produced a sound a bit soft and beclouded, as though it were perturbed by the task. I usually do not displace my headphones from the house (having invested a great deal of money in customs), but this experience has nudged me into thinking that maybe I should add a good closed can to my queue. Nonetheless, I will be spending more time comparing full-sized headphones on the DX.
This month of ownership has been a predominantly positive experience. Getting past the intermittent glitches and subpar battery life is not difficult when weighed against the sound quality; but that is not to say the DX100 is some kind of an end-all device. The DAC is tremendous and the amp above average (and a bit specialized) are my still-early ratings. Without having set my myself to the task of comparing, I will say the DX100 has wonderful potential as a portable device, but it cannot hold a candle to my home setup (which is several times the cost and to be expected).
