I have a usb Behringer Uphoria UMC204 and it seems to work fine at 44.1khz full duplex but anything higher than that I get consistent pops and clicks. I notice it's on the capure side of things as when I have it in playback only it's quiet. I have to say I'm testing this using JACK so this is how I noticed it on the capture only side of things. I'm not sure exactly whats needed to debug this issue. Any help would be appreciated. Thanks in advance.