What I’ve found is that I have these experiences with R2R DACs, and I either don’t have these experiences with Sigma Delta DACs, or I have them very little. This has been consistent with multiple DACs of each type, and is independent of the quality of the implementation. I’ve had Sigma Delta DACs that ’sound’ relaxed and natural, but the effects on me are not the same as an R2R DAC even if it isn’t as well implemented.
I’m not entirely sure why it happens this way for me, but I suspect the sound of R2R DACs allows my body to relax in a way that I don’t experience with Sigma Delta DACs. Please note that I cannot detect which DACs have this quality from a quick listening session, or from trying to assess how natural or analog they sound. I’ve had Sigma Delta DACs that score very well in those terms, but after extended listening they just don’t bring the same experiences.