I was curious whether the linear power supply in the Theta version "cured" the problem I had with the sound of the Hypex/Ncore Class D amp modules powered by their SMPS. Based on the comments, I guess not. I do not blame Theta or David Reich for not being able to pull off a trick that no one else has been able to accomplish with the Ncore modules.
The linear supply was never going to fix the problems with Class-D
The problem with class-d for now is that the massive switching frequency is too low (approx 700khz) for the filters to filter them out effectively without effecting the audio band in phase shifts and or even early roll off, in some cases. In the future when technology catches up to allow double or triple the switching frequency speed then Class-D will become a force to be reckoned with.
Here is Solutions Cyrill Hammer take on it also.
"if you want to have your product performing at the cutting edge it is not possible with today’s known switching technologies. In order to come close to the performance of the best linear design we would need high-current semiconductors that provide switching frequencies of several MHz or even GHz."
Cheers George