My SR505, as many know, has the Bartolini MK-1 pickups. I love the size, weight and feel of this bass. Ibanez four string necks are too small and the 5 stringer feels perfect. So, for that reason I love the bass, but am underwhelmed by the output. I've heard mixed reviews on the output issue with the 505. On one hand, i've heard criticisms about the pickups and others have said it's the over engineered pre-amp. I can pick up a set of Nordstrand pick-ups, but I don't want to spend the $$ if the pre-amp is muting the life out of them. One person said changing the pre-amp would be enough to liven up the stock pick ups. Do any of you have any experience on modding one of these?