I'm super excited about this new amp. I've been wanting a New Vintage Undertow 300 for some time now, but they just did an unofficial announcement for the 500D - a rackmountable tube/class d hybrid amp. Here's the write-up: "Two years of R&D has finally culminated in a prototype for a rack-mounted bass amp. We redesigned the all-tube preamp of our Undertow 300 to fit inside of a 2-space rack chassis and matched it with a Class D module that is over-designed to produce the greatest sounding hybrid bass amp on the market. We are calling this model the Undertow 500D - featuring a three-tube preamp identical to our Undertow 300/160, transformer-balanced and tube-driven studio direct out, and the ability to push two 8x10 cabs with a 2-Ohm stable output that is virtually unheard of in a Class D amp. The greatest part of this amp is that it weighs in at just over 13 pounds. The Undertow 500D is the perfect solution for touring and recording musicians that aren't willing to sacrifice tone and functionality for a light-weight, road-ready amp. This piece is currently being beta-tested by Rick Burch of Jimmy Eat World in Australia for the Soundwave Festival. Be on the look-out for a more complete product announcement, information, and a preorder for the amp in the near future. Email firstname.lastname@example.org with any questions regarding the Undertow 500D." Sounds like everything aside from the module is all hand-wired. I'm anxiously awaiting some more photos and some demos of the amp. If it's even half the price of the all-tube 300, it looks like I'll be picking this up one it is released!