"Also note that if your Bass as active pickups Kustom preamp sections have too much gain since they where made before active pickups."
I learned this firsthand last night. Plugged my active Carvin 5 string into my K250 and it sounded... well... ok.
Put it down then plugged in my Jazz bass with passive Bartolinis then my custom Tele bass with a passive Geezer Butler P-Bass pickup and BOOM... awesome tone again.