I couldn't understand thar part regarding Delta Sigma DAC with discrete ladder design, but that's not the point, let's not dwell on it.
I am not sure if you are referring to LPF anitliasing filter or LPF circuit whenyou mentioned the implementation of ROHM chips in N8ii. If you are referring tothe latter, I would like to point out that the LPF of original N8 probably is a better selling point (but we seldom mentioned it) because it use a pair of MUSES02 which is very expensive. The N8ii use regular (aka. high quality and cost effective) Op-Amp as LPF.
However, that doesn't mean we take a lite approach to the post-DAC circuit. We designed a 2x2 IV converter circuit between the DAC and the LPF, that's 6 regular (aka. high quality and cost effective) Op-Amp altogether in the post-DAC circuit, and will also involve a very demanding power supply implementation to keep this circuit operates in ideal condition.
Yes, we devoted a lot of resource to make sure the amplification and post-DAC circuit implementations are also top tier.