Fender Tonemaster FR-12 Input Requirement?

A quick question the answer for which I'm having a surprising amount of difficultly tracking down....

The Fender Tonemaster FR-12's input is expecting a Line level input signal, correct? If I want to plug in a Strat or an acoustic with a battery powered preamp output built in, I first need to run them through a modeler or some other piece of equipment to bump the signal from Instrument level in Line level first. Do I have that correct?

Any insight would be appreciated. Thanks!

You should be able to plug them directly into the input jack, but an acoustic really isn't designed to be plugged into that style of amplifier. The Tonemaster is a modeler built into a cabinet with a power amp and a speaker.