So I just got the mt-xl bass preamp off a deal on reverb. I plugged in into my amp and put all the EQs flat and turned each one to here the changes in tone. To my surprise, the entire 3 band eq was doing virtually nothing. The compressor worked fine but the preamp just didn't do its thing. The condition of this pedal was minor box damage so there no way it can be broken. Does the preamp only apply when it's used as a DI, or am I missing something.