how do i add reverb with this interface?

[camera_obscura]

ok so i found out i have this "audio creation" mode interface on my sound blaster x-fi card so i hooked up my acoustic electric. i've been trying to figure out how to add noticeable reverb (just to play around with it and learn), but i have no idea which direction to turn the knob and which knobs to turn, the manual doesn't explain this in detail. i tried different levels of turning the knob, but i couldn't tell the difference either way with the reverb effect at least. i don't really have any experience recording and adding effects and such, so i am totally lost on this.

this is how the audio creation interface looks like:


the manual only says FX return knob controls how much wet signal is returned but where should the knob be when there is 0 return and when there is ample amount of return? this screenshot shows the knobs as they were at default, the reverb knob at -144 on the infinity sign, the FX return at 0. my insert FX is on compressor because the recording levels are too low otherwise. i am also using microphone (without +20db boost) instead of line-in because again of low levels. if someone can help me out with a simple explanation of how this reverb thing works, i'd really appreciate it. thanks.