I have an ash/maple SB5000 with the J99A pickups and the active/passive option that plays and sounds great. I'm looking for a little more sound shaping ability because sometimes I have to go direct and want to keep it simple. The Carvin preamp sounds nice but I'm considering the John East J-Retro Deluxe. I like it's features and they have a pretty good sound demo on the bestbassgear website but a post from an earlier SB4000/SB5000 Roll Call thread makes me wonder if it would be a good choice. Does anyone else have experience with the J-Retro Deluxe in an SB5000 or another preamp that has worked out well. I don't want to throw away $350 trying something only to find out I never should have changed it.