Kinda wondering if there is a pad on the mixer channel that you are feeding?
Usually you wouldn't have that kind of problem.
Do you know what the mixer is?
Most common levels to the board are -4db or +10db.
If your gain stucture on the board is correct on the channel strip your feeding you should be able to get a good clean signal and let the PA work at putting out you carefully sculptured tone.
Like I said before most mixers should be able to handle whatever signal is given to them. The channel strip is all the preamp you should need after a DI.
Make sure your DI doesn't have a switch on it too.Some do for level matching.