I do understand your point. You don't believe deliberate DSP processing changes are the reason for the differences in the sound of the player with each firmware update. You may or may not be correct about that.
However, I do not think you understood my point. In response to my initial post, you stated that I was "totally wrong" and then took me to task for using the phrase "DSP processing tricks." DSP processing was but one example I threw out there as a possible reason for the sonic changes, but it was certainly not the primary point of my post (although I maintain that it remains a distinct possibility). My point was that Rockchip (essentially a subcontractor) may be entirely responsible for the changes to the player's sound and not iBasso. Is it possible Rockchip is making these changes (either deliberately or accidentally) as they develop the player's firmware and iBasso is either oblivious, or powerless to do anything about it?
If you look at my initial post, I even asked rhetorically, "Why would iBasso put so much effort into using the best hardware components in their DAPs, only to intentionally color the sound with DSP processing tricks?" My point being that perhaps iBasso is NOT intentionally coloring the sound - maybe Rockhip is!
IBasso's responses to our questions about these sonic changes have not been consistent. For a long time, they told us they were not aware of any changes to the sound at all. Now they're apparently saying they are making changes to the decoding library which account for the differences we're hearing. That inconsistency leads me to believe that iBasso may have no control over these changes.