When I compared the SR71b and the MKII three months ago I thought the MKII sounded nice but still below the SR71b in terms of noise level, sound stage and airiness. When I compared the SR71b and the MKIII at RMAF, I thought the MKIII has come up to the SR71b's level.
I was a little hesitant to draw too much conclusion from my audition at RMAF because the MKIII was a prototype and was not a final product. For instance, the MKIII at the show has only low gain that was functional even though there should be three gain levels (Hi-mid-lo). The balance and SE switch were also not functional. Also, the MKIII at RMAF could only demo SE input from the Solo as oppose to full balance As a result, I can only give some general or gross responsible impressions. I did feel there is some serious potential to the MKIII. I was very impressed with the fact that ALO can improve the MKIII to the SR71b level which I consider as no small feast and I told Ken that. I will wait for the final version to come out and do another comparison before I draw my conclusion as I know they are still doing some final tweeting.
One thing I do want to comment on is that I don't think the sound signature is that similar to the MKII even though Ken indicated that the design is similar to MKII with the exception of having 8 opamps. To me the change from SE design to balance design necessitate the change in sound signature in at least three areas: noise level, soundstage, and dynamics. Just based on that alone, the too versions are different enough for me very much like the SR71a and SR71b.
One last thoughts I have on the MKIII is that when judging a high end power balance portable the likes of MKIII, SR71b, and PB2 etc, one must use a good pair of Iem as well as a good pair of full size headphone. I have come to know that if you only use one type of phone you may draw a conclusion that may end up surprise you when a different type of phone is used. To me the full size phone frequently will mask slight or minor imperfection that a good iem monitor like the jh13 will reveal but by using only iem to test may also result in misjudging how full size amp will sound.
When Ken said that the MKIII is the most difficult project he has done, meaning more difficult than the Solo, I knew he has put a lot of effort into this project and has high hope for it. Above all, I hope and know that the success of the MKIII also hinges on the availability of a balance input source that the Solo is sorely needed. So there you have it Ken and David, just give us a balance dual Dac/dual channel Solo,and we will buy the MKIII