I purchased a Carvin Icon 5-string last November. I love the look and feel of the bass. The sound can either be very good or very bad. The low-end tends to be muddy, and the high-end can be extremely tinny, if I'm not very careful with the levels on the bass. I've read some posts about Carvin-owners switching out the pickups and electronics, and the general tone seems to be that the Carvin electronics aren't that great. I have a set of J99A/AS single coils, and the soap-bar humbuckers that currently reside in the bass. Neither set of pickups make me jump for joy. I'm looking for a "heavy, yet tight" sound, with big low end, yet somewhat clear tone. What are your experiences with Carvin pickups and preamps? I am open to switching out both, if it will improve the sound of the bass significantly. I also have an ADA MB-1 preamp, which I haven't added to my effects loop yet. I'm going to try to clean up the Carvin sound using the Parametric EQ and compressor, but I have no idea how successful I will be.