I have 39 ohm on output to 74ac157 and from 74ac157 also to dac.No pullup is needed. AK4121 outputs should probably have small physical size, roughly 33-ohm resistor in series (see attached image). The resistors should be located very close to the AK4121 output pins. What is coming out is RF so care needs to be taken to route it accordingly.
The 50-ohm transmission line in the image (sort of looks like a 50-ohm coax), is another thing to understand. https://www.allaboutcircuits.com/te...-life-rf-signals/what-is-a-transmission-line/
I saw, how look scope with/without this 39ohm, better with.
Now i have some problems with hardware, so now i need make some modification, i had to pull this chip up..