Thanks for the tips guys.
A friend told me that re cabling with copper solved the issue, but doing that is...a problem for me (I'm in Reunion island, means, finding a dealer would be sending away the grado for a long time).
Someone suggested the fostek HP-A8C to be the perfect match for the PS1000, it's a 1600€ dac/amp, though...
Could sold my burson dac and amp, but it's a hard decision to take.
Edited by deanorthk - 8/8/13 at 4:52am