The reasoning is a solution to a tough problem. Namely, how to compare integrated amplifiers with volume control to power amplifiers without. Anything else won't be fair. The gain on power amplifiers is not variable of course. But it is generally around the 29 dB that I test for. Where did that number come from? It is the THX certification criteria for amplifiers. So what I do is adjust the volume on an integrated amplifier until it hits 29 dB. I then adjust the input until I get 5 watts. That results in the type of input values you are seeing.
Yes, in a modern world I like to see us move to lower gain amplification and take advantage of the higher output of modern DACs. But the industry with some rare exceptions, is not going there.
Fortunately the difference is not large in many tests I have performed. Most amplifiers are distortion limited, not noise so gain won't matter. When it does change, it is only a few dB.
Thank you for your reply.
So actually, the integrated amplifiers are measured as if they were power amplifiers with 29dB gain, for comparability with power amplifiers.
I see, but is there any chance that they are also measured as we use them in the real world? (2V analog input level, 0dBFS digital level)
I mean, if I were looking for an integrated amplifier and looked at the measurements, I would see the SINAD results as I would use them and not as I would never use them anyway. Even if, as you say, there is not much difference.
Who knows, maybe some manufacturers have messed up the volume control at lower volume levels which could cause a difference compared to other manufacturers? What is not revealed by the current measurement procedure at near maximum volume control level. Or it could be something else.
The point is that I would like to see the SINAD that I can achieve at home under normal use.
Would you consider making such measurements in the future in addition to the measurements you have made so far?