As I mentioned in previous posts, I have bought a used Washburn MB-4 Mercury series bass. Took it back to the shop yesterday to have them resolder the jack connections, and while there I found that it does have Active Electronics. 1. What does this do for me and the sound exactly? 2. What are indications that the battery needs to be changed? I assume I would be able to tell by the output I am getting from the instrument? Will this be obvious to me, keeping in mind that I am back into this after many years away and am not familiar with the concept of active electronics in a bass? Thanks a lot in advance.