One more voice in the choir here asking "Why tube?" I own high end tube pres, but my favorite pres are solid state, and if you got a bunch of really experienced engineers together and asked them to name their one favorite mic pre, I would guess that over 80% of the answers would be solid state mic pre.
The problem is that its really expensive to build good quality tube gear at a decent price. There are actually low cost designs that are solid state, but they put a tube into the signal path for marketing.
I am not suggesting anyone rule out cheapo tube stuff, but if high quality recording is the end goal and the budget is tight, there might be better ways to spend your money.