I could try to figure this out myself, but I'm new to tubes and frankly, I'm chicken.

I have a Crate V5 and I'm loving it. I picked up an ART Tube mic preamp and I'm wondering if I can use this in front of the Crate as an additional gain stage to overdrive the Crate.

In particular, am I going to break something if I do this?

Can't guarantee it would sound good either. The V5 actually has an op-amp gain stage before the first tube preamp stage, you'd be driving the op-amp stage which might sound bad. Try it though, you won't hurt anything. I don't like how Crate calls the V5 an all tube amp when it clearly has a solid state gain stage, not that it's that bad or anything but I think they should make note of it.