bigkidz
If you care to look/study and compare most dac chip manufacturer data sheets are adhered to for implementation, even some (hiend ones) using even the exact I/V stage and buffer stage that’s on those data sheets.
"Some" (me, Audio Note above ) use different I/V and buffers, but as far as dac implementation itself they nearly all follow the data sheet protocols.
But doing discrete with this topic that's another thing again.
Cheers George