Reviving this old thread...
I just made a quick vocal recording with a stock u87ai and a modded one (won´t tell what type of change it is yet). If anyone is interested I can post the files. Personally I vastly prefer the sound of the modded u87ai in this case, it kind of leaves the good of Neumann (the colored midrange) intact but gets rid of the "bad" which to me is the smeared and dull highs of the stock models.
Anyone else did comparisons like this? Would be fantastic to gather some u87 mod comparisons with audio examples in one thread.
Rock!
Pat
EDIT: here are the files, same take recording of spoken voice, soft singing, loud singing 24bit 44,1kHz wav, no pad or lowcut engaged
http://www.wildcowboys.com/u87ai.zip