Hello, hope someone can help on this. We have the sigma ADAU1702 running on our PCB's and we have two designs using this processor, The differences on the designs are larger amplifiers and more of them. The issue is the same on both. Our output signal at the DAC's is clipping at 0.9Vrms on the positive swing as it should, but only 0.65V on the negative swing. We have the mini eval board and we get a clean 0.9Vrms on it. I have adjusted the input resistors and input seems to work as it should. The program is wired straight through for testing amps. Atached are the output at 0.6Vrms and 0.8Vrms on the green traces. The other is the input. 
Any insight would help. Thank you