Ha ha, nah man, set the gain switch to medium, and turn the volume knob up all the way, go through your mixer into the sample input only. I use one og them two RCA to Mono 1/4 inch adapters to sum left right into mono, that might get it louder, and on my sample screen my record gain is usually set between 40-60, never higher. The High Gain switch can cause distortion, that might be the fuzz you are talking about.
You did notice the record gain parameter on the sample screen didn't you?
Take it slower dude.