I'd reverse those numbers. I'd hit the preamp at 0dBVU. Any hotter and it's in distortion.
Actually 0dBvU is about -18 to -15 dBFS.
I never said it wasn't and I'm pretty sure it's -12 to -18dbFS. Anyways, I'm talking about pro tools here. -6dBFS is the point between the green and yellow parts of the meters. And that's the max point in which I mix and -5dBFS is the max I push the input. I should probably start using a VU plugin.. -_-