I can't believe there could be such a drastic change between the new and old version. We have KT DI's in a few studios here. That the KT would be worse than the Radial, that I wouldn't be too surprised by but when the MTR DI was so close to the Radial then there must be something wrong with the KT because it didn't sound at all like the other two. The difference was really drastic. The bass sounded like a banjo when played trough the KT.
Here's an awful attempt at plotting out the schematic after the transformer. My software wouldn't let me have enough components to draw the whole schematic in one document.

I've left out the 15 dB swichable attenuator between the secondary of the transformer and the opamp inputs. Also the groundlift isn't included as it's between the input and output and I couldn't draw the whole schematic...
There might be some mistakes in this so if there's something that makes no sense, please let me know and I'll double check.
Thanks for all the help so far!
[EDIT] forgot to say that it's a 3:1 transformer. The data sheet can be found with the rest of the pictures and documentation here
http://twin-x.com/groupdiy/thumbnails.php?album=309. And I don't know how the capacitor on the back of the transformer is connected. It's a ceramic capacitor that's connected to one of the primary pins. The other leg is also attached to the side of the transformer but I can't figure out where the connection goes...[EDIT]
[EDIT2]Updated schematic[EDIT2]
[EDIT3]Updated schematic to version 3. Fixed the 22K resistor to ve+[EDIT3]
[EDIT4]Updated schematic to include inputs and Earth link switch[EDIT4]