Hello. I have recently become obsessed with slap. Been at it for almost a year. I’m in the process of purchasing a MarkBass Amp. I have a Shadow pickup under my bridge. It has what they call a preamp. Runs off of a CR 2035 battery. Doesn’t seem to put out a lot of power. I’m looking for an actual preamp. Any advice of brands, size, style? Thanks very much, Ben.