I've got an old '90 Thumb 6 Fretless which came with bartolinis and a small (1"x1/2"x1/2") 2-band preamp, encapsulated with a midrange trim pot (sounds like "pick attack" ) The barts & preamp are being replaced by Duncans and the SD 3-band preamp (any takers?) but before they go I wondered if anyone knew what the preamp might be? A gent from Dana B Goods speculated that it too might be bartolini but it looks nothing like any bart preamp that I've ever seen. Not that any of this sounds bad - just way too "warm" for my tastes. My other Warwick has SD's & sounds perfect to my ears.