We're gonna do a write up to a logical approach to combining things. But in the meantime a good rule of thimb is if it comes with a volume knob (S.E.X., Stereomour, Crack, Mainline) it was not really intended to have a preamp (Quickie, Smash, BeePre) ahead of it. If it has no volume control (Quicksand,Seductor, Paramount) it needs a control preamp (Quickie, Smash, BeePre) or at least a passive controller (Submissive) ahead of it.