I have my Mk3 running for 400 hrs and believed it is fully burn in now. It is so good and makes my CD listening a whole different experience and I have to listen to my whole CD collection to redefine them. The oversampling mode is working on most of my CDs but some CDs are better without it. I don't know why. It is so much fun to listen CDs now. I was thinking to replace my Hugo 2 DAC and now I seem to happy with the DAC.