My TAD DA1000 makes a clicking sound (it sounds to me like a relay engaging but I'm not sure) that i can hear just before (circa 0.5 seconds) the DA1000 starts playing a track and just after it stops. I mostly use it to play music via the USB input but this occurs with optical inputs not just the USB. From what i can see, the click sounds when the DA1000 display changes from -- to the frequency of the sound file, e.g., 96 or 192. Has anyone experienced this with their DA1000? is this a fault? I'd be grateful for your feedback and advice