I just wanted to revise my thoughts on the Grado mpx3 combo. Steeleblayde reminded me at the meet at how evil the Grado bowl pads are. I replied that the bowls worked better for me with the 125s than did the flats. The upper midrange, and low treble was emphasized in a way that gave the music life, and made up for inadequacies in my systems (home/portable). In the last several months, I had grown a bit of a distaste for the 125s since my 2 tube amps were certainly Sennheiser favorites. The highs were thin and muted, and there was no detail, or slam (especially bass) - unlike how I remembered them from 5 years ago. I wondered how some folks could be such die hard Grado fans. Then today, I slipped on my flat pads, and expected what I had heard the previous times: the bass, and treble would roll off too much, the sound would be flat, and it would just sound boring. Not so this time! The sound of the old Grado I remember buying was back. The mids were sweet, and the bass was big, while the emphasized highs were thick, but not all that extended. It was fun to listen to these again, and through the mpx3 to boot!
I was baffled at how the change in pads could make such a difference. But after thinking about it, I believe that the firmness and generally good shape of my flat pads made more of a difference in the sound than the shape did. The bowls look pretty good, but they don't spring to the thickness they once did.
btw, the bass in the Grado-mpx3 combo is much improved. I can actually feel the foam vibrate on those made-for-boom-car tunes. However, I still don't think that the mpx3 is an amp for bassheads. I think that the consensus is that tube amps have difficulty with big-ass bass compared to solid state types w.r.t. frequency extension. Also, I think that the dynamic slam of solid state - (eg Creek, and cmoy variants) suits the Grado 125s better than tube amps such as the mpx3, or (especially) the MG-Head OTL.
You'll notice that I haven't listed many high budget amps, but my opinion agrees with my impressions at the meet during a comparison of the PPA to the mpx3.
Though I'm sad I've realized the solid state vs tube dilemma, I'm also glad about how gorgeous my classical cds finally sound through tubes and Sennheisers.