ADAU1701 i2s outputs low

I am using the ADAU1701 DSP at the heart of a audio mixer using the 4 x i2s inputs and 4 x i2s outputs With a PIC setting up and controlling the DSP. The pic supplies master clock and the DSP creates the LR and bit clocks, this all works ok, for prototyping I am controlling the DSP using the Analog Devices USB - i2c converter with Sigma Studio..

The problem is that the I2s outputs (all four) appear to be operating but only a small signal ( nominal DC = 2 volts with 0.5-1 volt low going pulses ie not getting near ground, and generally looking feeble.

Any suggestions as to the cause?

I have eliminated loading or connection issues, on the PCB, that is no loads nor shorts

Audio Signal Processors

data_output_level

i2s

SigmaDSP Audio Processors

adau1701