I've had a D11 module for a while that's been working great, but recently I've noticed a high-pitched whine/squeal on the signal. It happens at both inputs/outputs, and I've tried moving the grounding jumpers in all positions with no luck. I'm not in front of a spectrum analyzer right now, but if I remember correctly there are distinct spikes in the noise around 200Hz, 8kHz and 16kHz.
Any input on how to fix this and make my D11 usable again would be much appreciated. Thanks!