Now that TacT is dead
Is there an alternative? Aside from Lyngdorf?
Well there are some options, but none of them really do what TacT does.
The Trinnov Amethyst is supposed to be a fantastic unit, it is somewhat analogous in function to the RCS 2.2X. It is very costly, perhaps that is why software-based DSP at the source using Dirac or Acourate seems to be more popular.
Besides Lyngdorf, there are some other full digital amps out there from the likes of N.A.D. (not sure their higher end ones are still in production though) and Devialet. The latter can be configured with DSP crossovers too, although limited to 24dB/octave, and likely have the capability to do target curve adjustment, room correction, etc should they provide the software to do it. Which despite some rumors, I don't expect to happen. It would be interesting to directly compare the Devialet to Equibit amps; while I suspect the Devialet would be better, the Equibit amps are capable of very impressive performance even stock with very significant improvements from the modifications many of us owners had performed.
DEQX and Behringer are also still around, I think. Behringer is definitely a lower end solution. I am not very familiar with the capabilities of DEQX but know some manfacturers use it for active multi-amping.
If I had to replace my TacT setup today, I'd probably try to audition the Trinnov Amethyst and Devialet amplifiers, a very expensive combination for a multi-amped system.