Nothing much, socketed opamps, decoupling changes to my fav 3.3uF polyester. Removed a lot of filters that i deemed unnecassary. Isolated digital and analogue ground. Many more that i just cant remember...However the owner is not very satisfied with it saying that he is having noise issues which i never encountered during my testing period. the DAC will come back to me after almost 6 months in Australie. We will see how..Not to mention the PSU i built rosak due to postage and he had to pay a noob australian 40% of what he paid me...just to solder a transformer back...wtf! rclxub.gif