The DAC , all DAC, has the ability to “scale pcm” data before conversions. This level of scaling will then be applied toward the own chip DSP processing toward the conversions. There are different amplitudes for different pulses regarding differences between variations of the PCM encodings. Under a specific set of circumstances, the algorithms will have overshoots over the full scale values, which increase noises and clipping during the processing. The chips will then have to process harder and further to filter them out.
However, all of those mentioned above are all within the scope of the DAC chips itself. The engineers don’t need to do anything, just follow the data sheets and engineering white sheets. That is the reason why only PCM can be using Equalizer, because it allows a certain amplitudes to be adjustable and or attenuated.
Now, it is the opposite of that in order to lock the DAC chips, which is what we called an “optimized conversions”. The engineers “have to measures under a specific circumstances, instances” which are outlined by the DAC manufacturers and together with the experiences from the DAP makers itself. On top of that, the hardware of low pass filters will have to be measured afterward as well.
I am not saying that Ibasso team did all that. I just think that they did. Because those were the only reason to implement “analog gains” knob, and omitting the digital gain features. Logically, when analog gains are in place together with analog stepped attenuations, the digital sections are optimized. Those are how desktop systems are. Hence after the DAC, there will be a preamp, which is a mean to adjust the loudness by analog signals. Then it will come the power amplifier later.
I really don’t want to dissect this aspect of the game, because it involves a lot of different things, and where people would keep on asking for “proofs” etc… that means they are not interested, but rather just want to debate baselessly. Because for such an in-depth matters, they can research for themselves.
Then again, this is the reason why I love Ibasso, they allow firmware rollback. If you don’t like the new one, roll it back. How many companies would even allow this ? That is what I really meant