In case of RG and clipping, I wrote something about it, please read the whole thread until the end.
https://www.audiosciencereview.com/...ble-intersample-clipping-test.2231/post-60801
https://forum.cockos.com/showpost.php?p=2001665&postcount=30
Some important differences between RG and volume control are:
[1] RG is performed within the playback software and independent of audio device driver and APIs like ASIO and WASAPI.
[2] RG supports floating point operation and won't clip or compress values beyond maximum level (+/- 1.0). Regardless of the DAC chip itself is 24-bit or 32-bit, it is not working in floating point. Regardless of the effect is audible or not, values beyond +/-1.0 will be clipped by direct fixed-point conversion if not attenuated.
[3] RG stores metadata in per file and per album and the metadata are user-editable, which means users can customize the volume of each file and each album to their preferences and don't need to adjust the volume level manually each time during playback.
@Grave
I remember you quite respect NwAvGuy and JDS Labs, see what they said:
https://www.audiosciencereview.com/...review-of-jds-labs-usb-ol-dac.2244/post-61171
See page 4:
https://www.jdslabs.com/pdf/instructions-el-dac.pdf
For maximum signal fdelity, set the DAC to 24-bit audio and adjust digital volume slightly below 100% at your computer. Only control volume from your amplifer.
You can also see the IMD+N vs level tests in Amir's tests, it is not uncommon to see increased distortion when the level is above for example -5dB in many products.
Overloads caused by digital reasons should be avoided by using RG and/or digital volume control. Analog volume controls cannot deal with them. When the data are converted to analog, using analog volume control or not IMO is a matter of taste.