Hey Guys,
I've gotta defend the little 30 ART preamp. I just picked one up to record acoustic guitar, as my Electro Harmonix 12Ay7 pre is a bit underpowered for picking up my finger picking. I'm really happy with it. The Art MP did truly suck with my cheapo Ribbon, but with an SM57 or a Shure SDC, it sounds really acceptable. For 30 bucks, it's an incredible deal, I think. If you're planning on tracking EVERYTHING through it, I might think again. But for one or two tracks, or as a bass DI (another good application), it's sweet.
Oops - just realized I had nothing to say about tube swapping!