Got myself an Aria AMB-50B/FL electric acoustic bass. I've noticed a fault in the output signal from the bass to an amp or preamp. Basically, there is no volume or very little from the low E string, but ADG are all outputing fine with a strong well defined signal and tone. Any volume that is there for the low E is very low and distorted. It's certainly not a battery issue, that's the first solution I tried. I can only surmise that it's a problem with the piezo pickup inside. Does this model have 4 separate piezos for each string? If it does, what is the likely course of action for repair? Or could this be an indication of another potential issue? The basses own preamp for example?