I have been into diy guitar amps for a few years and I can't help but wonder how easy/hard it would be to build a bass amp. Now I know tube amps reasonably well but have never gone solid state. I do see that most bass amps are using Class D power sections, presumably to save on weight and pricey iron. So what would keep one from buying something like this and matching it with their (tube) preamp of choice to make an inexpensive hybrid? http://pages.ebay.com/link/?nav=item.view&id=370889080747 Ebay has tons of them, but they all come from China so not sure about quality or reliability. Thanks for your advice!