[KeithMoonwannabe]

Firebox sucks, sold mine years ago.

I would NOT, I repeat WOULD NOT!!! buy a $100-$200 preamp and expect an improvement in tone over the firebox preamps or that the added gain will be useable.

If you want a better preamp you will likely be spending about $1k to do it.

I'd suggest upgrading interface FIRST.

Then down the road you can start looking into better pres like the Great River, API, Neve, Trident, Daking, Sebatron, UA, Focusrite, etc. etc.

I think the converters and preamps in the Firebox are just garbage (hence I no longer own mine) so just do yourself a favor and get a better interface. Might I suggest you pick up a Yamaha N8 or N12. That gives you really nice pres and some of the best converters money can buy.