Can you expand on what you mean by 3D blob?  Definitely nothing I can relate to.  Are you sure it's not in the actual recording?  I know with my HD600 - especially with well miked live performances & binaural - my HD600 has always given me the feeling of actually being there (ie totally realistic soundstage - with width and depth).

think he meant the soundstage was dissected into 3 blobs...left right centre. 
a case of exuberant separation from the dac?

Yes when I said 3 blob soundstage I meant that to me it sounds like most of the instruments are either on the left, right or centre. Also compared to the Fidelio X1, the HD 600 sounds much less airy. So do you guys think this can be improved substantially by upgrading the DAC?