I have noticed a sizable number of questions regarding the potential improvements one can expect from a dac/amping the Audio Technica m50's. Having just combined my m50's with an E7/E9 I wanted to share my two cents. I compared the output of a computer with an EMU-202, an iPhone and a computer hooked up to the E7/E9 and I have to say the differences were astonishing. Listening to the song "Overture" by Dream theater on all three devices at the same volume, here is my non-technical (I am no audiophile) impression of the sound:
- iPhone: The song sounded really claustrophobic in comparison to the other two, with the instruments sounding as if they had been cramped into the same small space. Instrument separation was noticeably poorer and the soundstage was non-existent. The bass was muffled at times and some of the cymbals sounded harsh. I would describe the overall sound as being lacking in depth and clarity.
- Fiio E7/E9: What an astonishing improvement over the iPhone! The first thing that will strike you is the complete lack of hiss during the silent portions of the music. Rather than the music sounding flat, it is as if there is a little room built around your head with speakers enveloping your head in music. The bass is noticeably more punchy and each instrument is easily isolated and enjoyed. The highs are crystal clear without being harsh and fatiguing. There is an overall sense of clarity and detail that allows one to focus on air drumming and feet tapping and not worry about the music not sounding its best.
- From the EMU-202: The EMU alone actually had less of a hiss than just the Fiio E7 but the combination of Fiio E7/E9 was on par with the EMU in terms of background hiss. Many of the positives that the Fiio E7/E9 combination had were reflected in the EMU as well with the exception of the bass sounding relatively muffled at times and the soundstage being smaller.
One interesting and noticeable quality I noticed with adding the E9 to the E7 was that the E9 sounded deeper and livelier at a lower volume than would be required if one was using just the E7.
Overall, there is most certainly a sizable leap in performance from combining the m50 with a dac/amp that is in my mind worth paying double the cost of the headphone itself. For the doubting thomas's and the skeptical newbies out there- go ahead and invest in a dac/amp! Audiophile or not, you will be able to notice an astonishing improvement.