In a recent post regarding the numerous merits of the new Yorkville XS400H bass head, I stated that the single solitary complaint about this unit was the lack of a groundlift for the DI out. I really like everything else about this unit (especially the price). Would it be possible for a qualified technician to install a groundlift switch for the DI out on this amp? I realize, of course, that this will void the product warranty. But, with the addition of this feature, this amp would be virtually perfect. Also, what about the possibility of installing a level control for the DI out? Any opinions would be greatly appreciated.