I would speculate that something is dramatically different physically in the nano from the mini that makes a clear sonic difference. It could be D to A conversion, amplification, or characterist of power supply, or all three.
Also I should not rule out manufacturing variation as a source of the differences that I am hearing. These are mass produced, and they probably have pre-determined error tolerances that may or may not permit audible variations within the "acceptable" tolerance range.
Art
Also I should not rule out manufacturing variation as a source of the differences that I am hearing. These are mass produced, and they probably have pre-determined error tolerances that may or may not permit audible variations within the "acceptable" tolerance range.
Art