Originally Posted by RickenBoogie
It depends. You need to know what the output of the preamp pedal is, measured in Volts, vs. the input sensitivity of the powered cab.
Otherwise U just run around reinventing the wheel.
If that match isn't perfect it will "work" until you get to a gig and it just isn't loud enough or providing depth. Then U throw on a dedicated pre and BAM! full fidelity and more than enough volume and headroom.
Getting accurate specs can be difficult too.
So in the words of Obi Wan, "run Luke run!"