hey all, i'm thinking of swapping out the onboard pre on my parts jazz w/ Dimarzio Ultra Jazz, and wanted to know what your opinions on these pre's are. i have the J-Retro on my bass, but was wondering how the Aguilar pre would sound different. in a perfect world, i'd have Roger Sadowsky outfit his pre along with a variable midrange selector. but he's not down with fooling the mids on a bass. but, the Aguilar's frequencies are voiced similarly to the Sadowsky, especially to the all important 40Hz at the bass. any opinions?