There aren’t a hell of a lot of tube bass amps currently in production. Sure Marshall and Fender have ones that no one really uses, and Aguilar makes a tube power amp, but lately the only serious tube bass heads on the market have been the Orange AD200B and various Ampeg SVTs (II, Classic, Vintage Reissue, and Heritage). Keep in mind that I said on the market, because yes, Mesa/Boogie used to make a pretty ripping tube bass amp: the 400+. Well, Mesa is back in the game, but they’ve completely rethought their design.
Mesa/Boogie is releasing two amps, the Bass Prodigy and Bass Strategy. Essentially it’s the same design, except the Prodigy has four KT88 power tubes and the Strategy has double that amount. That tube choice is the big difference here. Mesa’s old bass amplifiers, as well as most of the company’s guitar amps, used 6L6 tubes. The KT88 is a higher wattage tube with more highs and lows, and less mids. Some of the more high-fi/high-gain heads use these tubes, like most VHT (now Fryette) models, and the new Twin Jet version of the Bogner Uberschall. The KT88 is also essentially the same tube as the 6550 (long story, just trust me on it) found in the Orange and Ampeg bass heads.
On one hand, this is a smart move. It’s obvious that a KT88/6550 is the more popular tube for bass (I personally prefer them, for what that’s worth). On the other, Mesa had their own distinct bass design and these new amps seem like they’re aiming for more of an SVT tone. But there’s room in that market, I suppose. The new Ampeg reissues don’t quite hold up to the classic ones, and the newer models like the II-Pro and Classic pale in comparison.
The higher wattage Strategy hasn’t been released yet, but the Prodigy is out now. Mesa/Boogie just uploaded some sample videos as a YouTube playlist here, and I embedded a couple of the more metal-relevant ones below. Personally I find them lacking context, so I want to get my hands on one in person. Maybe at NAMM, and hopefully they’ll have the Strategy there as well.