I'm considering an amplifier shakeup. My main head is a Carvin B800, which I have had solid service from, but I'm craving a shakeup, as the Carvin sounds a bit pedestrian. I would be pairing the new head with various Epifani PS series cabinets and play mainly five string basses. My general tone quest is a largely old school with a touch of modern sparkle thrown in. I've never owned a Mesa or GB product, so I'm not particularly biased either way. The notion of a tube preamp is appealing and I know that Genz and Mesa enjoy solid reputations, so any suggestions from those with experience are greatly appreciated. Oh, and of course, I'm open to other brand/model suggestions.