Preamp Pedal for 12 string bass

[AtomicPunk]

I just bought a passive 12 string bass (Waterstone TP-12) and all of the other basses I use are 18V active basses. When I plug in the Waterstone, it is missing that low end that the others get with ease. Thinking about adding a preamp pedal in the chain to get that low end grunt. Not distortion, just OOMPH and the booty shaking bass I'm used to getting from my Bongo, etc.
I'm unfamiliar with the good / bad / ugly of pedals, so looking for what's good, etc. Any recommendations?
THANKS!

[vegas532]

The MXR Bass D.I.+ is great for adding fullness and heft...even a footswitchable distortion if you so desire.

[CopperheadLXXIX]

If you want a really small and simple solution (not a ton of knobs) get a [sfx] Red Dragon. With the tone down and the gain up it doesn't distort, but will give you a really nice, deep "tubey" kind of growl. I use a custom version of the Red Dragon at the front of my chain for my Dean 12 String Bass.

[RickenBoogie]

An EQ pedal would also work well, like the Barber Linden, which can add a literal ton of low end.