These are known for being a really hot signal bass, and pretty much everything that's been posted here has some merit. My advice for things to try that cost you nothing but a few minutes time; lower your pickup first. There will be some trial and error with this, but adjust the height a little at a time. Down just until you get a slight but noticeable drop. Next, start with your preamp controls rolled all the way down, then just add a little at a time to get the sound you want. When your ready to play, open your volume all the way, and then roll it back to about 8/10. This should take the edge off but leave you with plenty of volume. Last thing, if you're comfortable with soldering, and have the 4 wire pickup, wire it for parallel instead of series. If those measures don't work for you, look up
@LowEndLobster on the tubes of you, and check out the series he did on modding the Sub series basses. A wealth of info there. Best of luck!