From Rick Naqvi at PreSonus:

"How to use the Blue Max to grunge up drum loops: The Blue Max has a very large amount of input gain because it was designed to be able to accept instrument level signals and drive them straight to tape. Henceforth, when you plug in line level signals like a drum machine or sampler, you can crank the input gain of the Blue Max up to achieve a slight amount of distortion. This sounds killer on loops as an effect, as well as squashing the daylights out of it. Use the "Squeeze" preset which is on EFFECTS 1. Crank the input to the desired amount of trashiness, adjust the output and you're done!"