Hi, I have an SX jazz bass with active Bassline pickups in it. Recently been having this strange problem. Every time when I plug it in, the level is substantially soft and it's slightly distorted. After like 5-10minutes leaving it plugged in the sound will eventually go back to normal. If I start playing it, I can hear it going back to being soft and distorted again but after maybe 10minutes leaving it plugged it the bass will function as usual. (sorry for the poor explanation, not too sure how else I can describe the problem :/ ) I have change the battery. Anyone have experienced this before? and know how to fix this?