Sennheiser HD485, has velour and oval shapped pads, while reading a thread about a mod to use them with grados i found out the pads can be easily deformed to become circles
is a very tigh fit and a bit deformed. but it fits.
As for the sound, for me and not sure if applies for somebody else, got a tip better because now my ears are inside, i have big ears and with the original pads these werent circumaural for me, the HD485 has larger inner diameter so now my ears are touching the driver housing, which can also be uncomfortable, since there is no cloth ot pads inside, my ears touch the plastic, deeper cups could be obtained by stuffing the pad, not much though, since the fit is very tight and the new pad is already streached out.
overall, sound didnt change, and if any it got better, but simply because my ears are closer to the drivers now.
it is also an improve as for comfort but it could be better.