The LM4549B must be initialized by using RESET# to perform a Power-On Reset.
Don't leave unused Analog inputs floating. Tie all unused inputs together and connect to Analog Ground through a capacitor (that is, 0.1-µF).
Do not leave CD_GND floating when using the CD stereo input. CD_GND is the AC signal reference for the CD channels and should be connected to the CD source ground (Analog Ground may also be acceptable) through a 1-µF capacitor.
If using a non-standard AC Link controller take care to keep the SYNC and SDATA_IN signals low during Cold Reset to avoid entering the ATE or Vendor test modes by mistake.
The PC_Beep input should be muted if not used since it defaults to 0-dB gain on reset, unlike the mute default of the other analog inputs.