It has been years since I had considered building one of these, life has gone up and down, left and right, I hadn't used headphones in a long while. I finally got back into the hobby. Got another pair of MS-Pro's and bought funch's EHHA from a member that had purchased it from funch couple of years ago. This thing sounds amazing! Just such an effortless presentation of sound, highly detailed, excellent instrument separation, no grain, its smooth but never syrupy. This is it folks.
The tubes on this are still the original A Frame German GE's, I have ordered a set of NOS Pope Holland 6GM8's, anxious to hear those.