I have an Ampeg BA-115, and the volume keeps fading out right in the middle of my playing. It just started doing this recently, after I built my own active bass, but my passive jazz bass does the same thing, and so does my 6 string guitar. I do have the active bass plugged into the active input when I play it. I run it through a distortion, wah, and octave pedal. Am I doing something wrong? Any suggestions?