Grinder 12-String Bass
The Grinder 12-string bass was built by Alex Berezin from Moscow, Russia. Alex has built a number of 12-string basses over the past decade. While this bass served Alex well on stage for a few years, it has now been retired due to neck issues.
ALex’s Advice On bubinga
Per Alex, “Due to string tension this bass has developed a crack in the neck that precludes its further existence as a 12-string bass. It was definitely my most-used 12 live; the heavy use had it's way with a piece of Bubinga in the middle of the wide but thin 3-piece neck. The moral of the story: DO NOT use Bubinga in a 12ver neck, ever! Every single 12ver I've had with a Bubinga 3-piece neck has developed a similar problem, I had to scrap them all. (Not to mention that Bubinga is now regulated via CITES so it's problematic to sell or buy such a guitar anyway.)
The only one still alive is a 15-string bass, but it has a much wider neck, which probably helps. To add a short disclaimer though, while my personal experience with 3-piece necks with Bubinga in the center is pretty much all bad, it's still obviously possible that other people might have better luck. This is just a friendly warning to the others who might want to try it out.