Speaking of DI - i just did a gig - connected Main Output (XLR) to FOH. I had all Ground Lift pressed. But there was big hum from my channel and drive everyone crazy. So the sound guy had me take out the XLR and connect instead with DI. And like magic the hum disappear.
BTW - this is the DI used:
http://www.radialeng.com/r2011/jdi.php
The sound guy told me there is no ground in that building and the only way to get ground is to connect with DI. I was surprise with all the ground lift on the back of the KPA. So may I have to carry DI rather than connect direct with Main Ouput to FOH. Any suggestion on this?