I've read that the aguilar onboard preamps (dont remember if it was one or both of'em) are active yet are able to have passive treble and bass controls. I've also seen this setup in of those Flea model Modulus basses. Could somebody explain to me how this can be/works? And does it come standard on the preamp or is it something you have to get extra? Ofcourse, if you've played through one before let me know what you thought, I'm looking for something to funk up my spector and bring it to life. I love the ballsy sound of all passive, just not to slap with.