Much less hassle will be swapping to a piezo pickup, as BassBod suggests. They slip in the wings of the bridge, can be bought cheaply (a good one like an Underwood, Shadow or BassMax will cost you £50+ used but there's acceptable ones on eBay for like £20), and you won't have to change strings (I hate swapping DB strings as I end up with cramped hands!). Ditch the Schaller! Or get a better mag ... but easiest is to get a piezo IMHO