Do iFi products really use some kind of R2R?

I was reading this article:

The guy behind ifi is explaining the reason of using DSD1793 for almost all of their products. From the nano to even pro idsd dac, a $2500 dac, use this chip by Burr-Brown.

Is this dac really that special? is it really R2R for its upper 6 bits?

I was listening to a sound sample by audiocheck and at normal listening level, I was able to only hear up until the 8th voice which equals the 8th bit (correct me if I’m wrong).
If the test I did means I can only hear the upper 8 bits, this 6 bits R2R isn’t far from a true R2R dac, right? What do you think?

Multibit doesn’t always mean R2R, and I can’t find any information that the chip they’re using has any R2R section. And that sample is not supposed to be listened to at constant volume, you’re supposed to keep turning it up, trying to keep hearing the voice at the same loudness and looking for the level where it starts to sound bad or gets overwhelmed by the noise. But since those are synthetic samples meant to demonstrate quantization noise, you will hear more noise from the samples themselves than from any decent modern DAC regardless of architecture, so you can’t use those to tell the difference between 1-bit/bitstream Sigma-Delta, multi-bit Sigma-Delta, R2R or whatever.