A bit later than I promised, but here are some more thoughts about the Yamana EPH-200. They are built to entertain, but in a plot twist, they don't accomplish that via the normal route of bloated mid bass and overemphasized treble. I'm a fan.
Design/Construction: A micro DD (6mm) in a long, barrel-shaped shell designed for pretty deep insertion. Kind of like Etymotics, but with a wider bore barrel that fits just a bit more shallow than the Etys. It's comfortable for me, but might not be for everybody, that wide nozzle might not be kind to every ear canal. The shells are made of polished aluminum, very lightweight and sturdy feeling, and have a nice appearance. Unfortunately, I did find that they can scratch easily if you're not careful, as I accidentally banged the left shell into the corner of my desk, and it did leave a slight mark on the finish. I do have the sense that they are built to last, however.
EPH-200 has some nice custom touches, like the mmcx connectors/cable that adjusts for different types of wear/fit and doesn't let the male end of the plug rotate in the socket. The cable is thin and a bit stiff, but the mmcx connector adjustment and chin slider combine for a stable and comfortable over-ear fit for me.
EPH-200 comes with custom, double flange tips. They worked pretty well for me in terms of sound, but felt a bit stiff when inserted deep into my ears. Out of curiosity, I experimented with many, many different types of tips, most of which were fully unsuitable for the EPH-200. T500 clones (barely) fit over the nozzle, but seemed unstable, and didn't allow for the proper insertion depth. Various wide nozzle silicone tips showed promise, but then just slid all the way down the barrel, pushing the outer grille flush to the end of the tips. I had a hunch that KZ Starlines would work, and after serious effort with some tweezers getting them on, they did the trick for me in terms of comfort and fit.
Isolation is superb. Possibly the best isolation of any IEM I own. Like having ear plugs inserted into your ears.
A fairly large but standard design case gets the job done for storage. The overall packaging/boxing experience is professional, but not particularly flashy.
Bass: Low end is geared towards sub bass extension.. Offers satisfying rumble, without ever losing control or becoming a distraction. Mid bass sits behind the sub bass, but has good presence and is not at all boomy or bloomy. Speed is good, as you might expect from a small DD. Only minor complaint on the bass is that it doesn't always sound as "musical" or "melodic" in the mid bass as some of my other IEMs that excel in that regard. It's a minor nit-pick though - the low end on display here offers impact, agility, and accuracy, and does it's job nicely.
Mids: Felt slightly recessed to me at first, but after figuring out the fit and after some burn-in, they're actually a treat. Mids are detailed, layered (more on that in a bit), and natural. Vocals sound great, with good accuracy and natural timbre for male and female vocals alike. Well recorded harmonies are particularly expressive and impressive. Electric guitars and synths have good texture and bite, while acoustic instruments sound natural and visceral (think: strings buzzing, fingers squeaking on strings).
Treble: Highs are not over emphasized. Feels like it was tuned for effortless, long listening sessions. Cymbals and high hats have good energy. Female vocals in the upper mids/lower treble have no "shoutiness". No sibilance. Highs offer up just enough energy and sparkle to provide a natural-yet-vivid presentation for genres like rock and pop. Treble is not peaky, overly bright or shrill, but also don't offer that last bit of extension and air that many people appreciate.
Other Thoughts: This is where things get interesting. The deep insertion fit makes the sound stage very intimate initially. Out of the box, I was somewhat disappointed, as the stage was fine in terms of width, but felt very linear, without depth or height. After 30 hours, my perception has changed considerably. Good height and depth are conveyed for an IEM. The overall stage feels well rounded, and not over extended in any relative direction. The sound stage dimensions are complimented/enhanced by the layering and separation the EPH-200 offers.
Layering and separation are stand-out attributes. Harmonized vocals stack up alongside each other, distinct and clear. Instruments occupy their own place in the mix .Drum fills sweep across the drummer's kit. Lead and rhythm guitars are placed apart from each other on the stage. The overall presentation delivers a lot of excitement, with different elements of the mix coming at you from different locations. The layering lends the perception of additional depth to the sound stage, and gives the otherwise modest highs an extra element of expressiveness due to their ability to be distinctly placed in the mix. Well mixed live recordings shine.
Timbre is good, very clean and natural sounding. It sounds neither warm, nor bright/thin. For those who enjoy the natural tone and timbre of a nice DD IEM, the EPH-200 delivers. Reverb and echo are rendered nicely. Detail retrieval is good, but not on par with either of the Etymotics I own (ER2XR and ER4XR), and probably not quite at the level of the JVC FDX1 either. However, I never feel "wanting" for detail with the EPH-200, and frequently find myself noticing new elements of songs or their production due to the layering and sound stage properties.
EPH-200 seem easy enough to drive, I find them easier to use plugged straight into my phone than the ER2XR, for example. I mostly listen to them with my Radsone ES100 or my desktop amp, and they scale well with the improved sources.
Summary: I like the EPH-200, a lot. Their vivid midrange and deep sub bass provide plenty of entertainment and excitement. Their approach allows the EPH-200 to act as a nice compliment/alternative to brighter and more analytical sounding IEMs as well as typical "commercially tuned" v-shaped sets. If the physical fit and insertion works for you, they're capable of hours and hours of extended listening sessions without fatigue.