From what I can understand, there is nothing we can do to design a better DAC than we have available now. Any improvement will not be audible, although we may be able to get them to consume less power. The same goes for Amps, we know what there is to know about them and there is nothing we can do to increase their fidelity. The 16 bit 44.1 kHz format is able to record and reproduce sound waves perfectly, and no increase in sampling or bit depth is going to improve the listening experience. So have we achieved audio perfection? Is there anything we can do to improve the experience of the listener outside of improved design of headphones? Even headphones are old technology, I'm not sure why some headphones command such high prices when we know how to make a transducer with flat frequency responses.