I first bought a TacT 2.2X around 2006, because I thought its DSP was more transparent than the EQ in my Cello Palette Preamp. Some years later, I sent it out to a mod shop in California, who never returned it. So it’s hard to say how it compares to today’s best. In terms of flexibility, I’ve never found its equal.
The ones I’ve tried lately that I think are really clean are the Weiss EQ1 Mk 2 and the Anthem STR Preamp. The latter does its DSP at 192 kHz (not sure of bit depth, but at least 32) and is clean and transparent. ARC when implemented on that device can make changes without diminishing the soundstage or hardening the sound, not true of all DSP units. I think that in the last year or two, DSP for consumer audio really has come of age.
The ones I’ve tried lately that I think are really clean are the Weiss EQ1 Mk 2 and the Anthem STR Preamp. The latter does its DSP at 192 kHz (not sure of bit depth, but at least 32) and is clean and transparent. ARC when implemented on that device can make changes without diminishing the soundstage or hardening the sound, not true of all DSP units. I think that in the last year or two, DSP for consumer audio really has come of age.