I spoke personally to one of the original owners of Sonic Frontiers. He said that they are "focusing" on their home theater Anthem line, and that the SF tube products will not be produced for the time being, but stressed that this does not mean permanently. I guess it is anyone's guess whether production runs will occur in the future. They have plenty of parts and service techs who know the products, so customer support for all the tube gear they made will be there, hopefully for a long time.
I believe Paradigm said, hey, we can make a lot more money on the home theatre stuff; we want you to stop the tube production for now.
It's a downer, because the build quality, finish, parts and sonics made this a product value unlike many other tube manufacturers offer. Look at a 11 pd. Audio Research preamp, then look at a Sonic Frontiers preamp. AR gives you SO little for the money, though their stuff sounds good.