Using a WA6. I did change the rectifier, had been using a Sophia. Already a bit better, but the muddiness continues. And the WA6 is just fine, honestly. It does make me wonder if a brighter sounding dac would help. I have a Fiio E10 right now, not ideal, but It really is just the clamping force that is forcing them on my ears so hard, just is simply too close. Looks like you can widen them a bit just by stretching the cans outwards, but I don't want to do it too much, as the headband is plastic.
Like I said, I'll just wait for now, I think. Maybe a bit of air will come later. Simply bending them a bit has already helped. I also need time to adjust to the signature, coming from listening to almost purely PS500s. I will say, I'm super impressed by how it renders cellos. Just enough midrange juiciness that the cello can really speak out in its own voicing. Very satisfying, the PS500 does many things well, but allowing a cello to speak out of the texture of a quartet is not one of them.
edit: Ya, instant love, just need the pads to hold the drivers about 2mm further from my head. Glad I bought these, they will eventually sound amazing I think. Makes me wonder about the HD-600.