Modding VTL tube amps for XLR- possible?

Seriously considering purchase of VTL ST-150, but am wondering if anyone has ever tried to convert one to accept XLR inputs (single-ended inputs only). The rest of my equipment runs fully balanced, so it would be great to be able to convert the amp to run fully balanced as well...
Adding XLRs would be easy but since the amp does not have a balanced input stage you gain nothing. You would most likely reduce the resale value a great deal as people take a dim view of mods not done by the well known "modders". Is that a word? I guess it is now. ;>) Hope this helps. Don
Thanks Don- I was afraid that would be the answer!