From BearFoot facebook:
Rooster: looks like we will have 3 variations - this was Ken Fischers' favorite booster and he likened the variations to swapping different brands of preamp tubes ... the RRB has 33 db of boost- same as adding a preamp tube stage to your tube amp ..... and if youve ever swapped tube brands and heard the difference between Amperex and Telefunken or even just Chinese and Russian tubes youll get the span of the 3 Roosters.....It has the basic EQ of a bridge pickup with upper mid push and top end sparkle.......