I realize that the topic of crackle on playback has been discussed at length but I think I have a new version of the problem. By way of background, I am using Media Center 20 on an HP all-in-one and I am using two USB outputs. The first runs to a Bricasti M1 outboard DAC and then to a Cary SLI-80 integrated amp. This path works just fine as output to my speakers is perfect and when I plug my headphones into the front of the Cary, that sound seems just fine as well. The second USB path runs to a DAC1 Pre that I want to use with headphones as well but when I try the headphones through the DAC1 I get intermittent crackle. This occurs when I play the same WAV file back with all the same settings on both paths - perfect through the Bricasti and Cary and crackles through the DAC1. I have tried playing around with the buffer size and most of the other variable that I can identify for audio playback but nothing seems to change the crackling. I infer that the problem is specific to the DAC1 but I can't figure out what it might be. Does anyone have any thoughts? Thanks.