I bought the T90's couple of weeks back. Yes they have a sharp top end & need a warm source to tame it, also burn in reduces their brightness ( I am at 200 hrs now). I use a Woo Audio WA6 amp & it has managed to tame the top end by a good margin & Bass & mids are the most balanced I have heard till date (i own 5 other HP's, these beat the HD 650's hands down in terms of engaging the listener with the music). I use a very mild EQ on Pure Music , -2db cut between 5k Hz & 10K Hz . I use a Weiss Int 202 fire wire to spidf converter & do not hear any noise.