My understanding is that coming out of the preamp is a 'line level'. And if your multiitrack doesn't have a line level input and you go thru another input you are just going thru the multitrack's preamp, which is what you are trying to avoid even though you may have 'warmed' up your sound with the external preamp.
But I really don't understand it, so that's why I'm asking. I'm looking a purchasing a multitrack, something like Korg 1600, Zoom1608,Boss1600. And the Zoom actually has a 'line level' input, so I wanna' get a better handle on all this before I make a move.