I agree with Kent, the USB disconnection is most likely going to be either a crappy USB cable, the DAC in the CXA 81 dropping off or the Raspberry Pi itself being underpowered (if you have multiple peripherals drawing power with an inadequate psu).
Firstly connect using a short, robust USB cable. Also try enabling the "USB (UAC2) fix" in Moode's system settings.
Firstly connect using a short, robust USB cable. Also try enabling the "USB (UAC2) fix" in Moode's system settings.