pauldeg

All good suggestions, will also try to disconnect my Mac from power outlet for measurement session, thanks!

Yes, I did loopback calibration for Scarlet Solo, if that's what you mean.

Could be, "direct" mode was on though on Scarlet Solo. I'm mostly surprised that noise levels were much higher compared to measurements...

Yes, I played with levels and was able to get reasonable measurements, but it was rather tricky, basically I had to reduce input...

OK, I switched to creative SB usb card, the card itself plays very well with REW and shows reasonable 0.05% THD-N, I'm even able to...

I did, when I check levels in REW everything looks good, I'm able to match out and in around -12 dB, but then when running actual test...

I'm trying to measure Scarlet Solo USB audio interface internal noise and THD, and it shows very poor values no matter what I do. This...