IVX

I think it's a good idea to test the DC bias on the PH-10 XLR output, and compare with limits here...

But how did you burn it?? Poweramp?

it is https://www.diodes.com/datasheet/download/ZXTC2045E6.pdf The ESD protection diodes of the OPA1612 are "bypassed" with external...

right, usually the only 10ohm res is opened.

10ohm and noise? Come on.. any thik-film is ok.

wery well, you need to replace these burned 10ohm resistors, and think about how to avoid input overvoltage in the future.

if all 0603 10ohm are ok, I would take off the IC10, it is part of the input opamp(1612) protection, 5A N/P BJT pair.

As I understand, your Scaler had worked properly, but now it has a lot of distortions? In that case is most probable that the 10ohm 0603...

You are 100.00% right ;) 4398 is a dino from 1990th, it is the same but without HP buffer and no DRE.

You seem to keep mixing up the CS4398 and the CS43198.;) Very different parts! Yes, the CS43198 does not need an op-amp output stage...

16 bits -90dbfs looks ugly indeed.

The best way to get GND is a crocodile-clamp from the DAC's USB-C shield.

hm, hard to say but if it's not hot and works with no hum noise, I guess no problem.

oh, there is some old-school muting that also may add tons of distortions. CS43198 has muting too, hence, LPF-opamp is really redundant ;)

I guess the LPF on 5532 is redundant, and only increases the THD+N.