Hi m3_Arun, thank you very much for your clarification, and for the thread. By reading all converstions in thread, I have manage to clarify a lot of concepts, I have read a llitle about audio tech before (The Art of Digital Audio), and all along the way sigma delta ADCs looked suspicius, it is...

Hi, this is my first post here I am absolutely not an audio expert, just an enthusiast... so I and the thread proposer are even :)   Due to biological limitations, the "real" (physical) audio signal can never be heard, a lot of the audio perception is inferred as the result  of postprocess...