Sorry to hear you're still not passing sound. As you know, it's always hard to troubleshoot a prototype where both the hardware and software are unproven. It's also hard to troubleshoot remotely, but I can offer a few ideas.
Make sure the 1701's PLL is locked. There's no output pin to confirm this, but a simple check is to bring the antenna of a small FM radio near the chip -- if working, it emits some EMI at 98.3 MHz (roughly twice the MIPS frequency). I assume you have checked your schematic against a known working one (such as that of the ADAU1701MINIZ eval board). In particular, check the two PLL config pins to make sure you're running at 48KHz sample rate (divide by 256 with a 12.288 MHz crystal) -- the default signal flow assumes this. If your hardware is set up for a higher sample rate, you'll need additional I2C register writes to configure accordingly.
Best regards,
Bob