This site is such a mine of information, I should have read here before posting on head-fi! The information below is thus mostly old news for you guys, but I thought some listening impressions , however brief it was though, might still be welcome:
I went today to the fall headphone festival organized by Fujiya Avic in Tokyo. I only wanted to check out Stax's new prototype and Ultrasone's Edition 10.
Note that I don't have much listening impressions because one literally only has seconds to sample the gear until the seat must be vacated for somebody else… Yet, one can at least get a very rough idea of the tonality of a headphone, probably not much more so notes below are only worth so much, you are warned …
...
Before listening to the new prototype, I had a brief chat with the Stax representative. Unfortunately I do not know who he is, but a very nice senior person. I speak a little Japanese but frankly not well. So please forgive if some of the following is inaccurate due to some loss in translation / foolish interpretation .
First, I asked when it was going to be out: first half of 2011 is the plan. Next, the price: 300k to 500kJPY. Third, a matching amplifier: yes likely, but not in the immediate future. So probably we can't expect an amp to be released at the same time as the new headphone. He did mention though that the current top of the line amplifiers from Stax can "drive this headphone without any trouble".
Next, I asked about the diaphragm: it is a new design. Something about a complicated manufacturing process because their are three layers assembled together by heating process. The thickness is higher than Omega 2 because while a light / thin diaphragm is good for transients, it is affected by "low" frequency resonances. This time around, it would appear that Stax has tried to achieve maximum stiffness (and damping, hence the multiple layers?) with the new diaphragm. Anyhow, it is a complex manufacturing process which I guess is driving the cost up.
Next, the frame: aluminum, much stiffer than Omega 2 frame. The weight is a bit affected but I did not feel the headphone was heavy at all. The frame thickness may change slightly in the final version but looks like the looks is pretty much set (I find it really beautiful, the Omega2 looks cheap in comparison, and well, it will be ).
Last: the name … Of course he did not say but this is a new series, beyond the Omega. The Omega 2 will remain on sale. When I asked about anniversary, he said that this is indeed a point as Stax is reaching 50 years in existence…
Now to the listening. Again, it was too brief but I could go for two rounds fortunately. I listened on the 727A, which is nice because it's also my own amp. The source was a Marantz SA-15 or something like that, not very high end.
Well, what jumped at me is that the tonal balance is quite different from the Omega 2, it seems definitely more tonally neutral while the Omega 2 has a warmer tonality on this amp.
The highs of the prototype are very present but absolutely not shrill or detached from the rest. Next, the bass is absolutely there but tight. In comparison the Omega 2 does feel like the bass could be firmer / more controlled (again on the 727A).
It does seem like the headphones are quicker sounding than the Omega 2, and dynamics are improved. Too short listening to say for sure though, some of this might have to do with the more neutral tonal balance.
Finally, the ease of drive: while I listen to the Omega 2 at 9-10AM at home, I was at 12-2PM with the new prototype. Mind you, the source might have an impact on this. My yamamoto D/A is a rather hot source.
Overall, I have to say I was very impressed. It feels very much like a step in the right direction based on this short listening experience. The price is going to be steep, but it appears Stax is trying to get the top seat for best sounding headphone in production!