Thanks Dave,
The slave mode was a real easy fix as its just a case of removing the solder between the 2 pins on the 1937.
Its frustrating that this was missed under the schematic review but I guess thats all part of the micro electronics life, I'm learning this on my first ever project lol
Do i need to move both LRCLK0 and BCLK0 to LRCLK3 and BCLK3 to solve this issue?
Graeme