For curiosity i compared the etc with different filters on the project box s2Can you explain it? I chek the link ak240 did you find the etc result good?
I compared the etc from the ak240 with etc from nos dac and it's totally different looking. Wich is better?
https://reference-audio-analyzer.pro/en/report/dac/muse-audio-4x-tda1543-nos-dsc.php#rw31
Optimal transiant looks like nos dac
https://reference-audio-analyzer.pro/en/report/dac/pro-ject-pre-box-s2-digital-transient.php#rw31
And fast roll of looks like classic ds dacs
https://reference-audio-analyzer.pro/en/report/dac/pro-ject-pre-box-s2-digital-fast.php#rw31