I'm experiencing some strange noises with my ADAU1761 eval board. It kind of sounds like clock noise, but it also is changing in frequency and changes pitch. It's a bit like whistling wind.
It seems to enter my signal only when I turn on either of the AUX L and R inputs (registers MX1AUXG and MX2AUXG). If these are muted, then all is quite, and my differential inputs sound clean.
I should also mention that my DSP core is very simple. I have stripped it down to pinpoint the issue. My schematic only consists of inputs 0 and 1 going into a two channel fader and then go my DAC0 and DAC1 outputs.
Has anyone else experienced anything like this?
Any help would be greatly appreciated.