The FD3's and TC preamp sound great together, as long as you like a very modern tone; the TC has a similar EQ curve to the B7K when set clean, meaning a wide boost around 100, a sharp cut around 350 and narrower boost around 3k.
My AB is also ash/wenge, so it's already a very present sounding instrument, and with the TC engaged things start to sound very aggressive very quickly; with steel strings it's especially easy to get harshly bright on top if you aren't careful.
That being said, the way the bass sits is like nothing I've ever heard before: bottomless depth with tons of clarity, so much so that it's actually forced me to clean up my technique.