57Note: Dolby Digital Plus format is only passed through the HDMI ARC connection.Setting up a digital audio connectionYou can connect the TCL • Roku TV to an external amplifier, receiver, or sound bar by using either ofthese two connections: HDMI ARC – The HDMI Audio Return Channel enables the TV to output digitalaudio on one of its HDMI connectors. The connected amplifier can also functionsimultaneously as an input source to the TV, if needed. To use the ARCcapability, you must connect an HDMI cable from your amplifier’ HDMI ARCconnector to the HDMI ARC connector on the TV. You also must:o Be sure your HDMI cable is certified by HDMI.o Select the appropriate setting under Settings > Audio > Digital audio out, as explainedin “Changing the audio mode” on page 56.o Enable HDMI ARC under Settings > System > CEC, as explained in “Enabling HDMI ARC”on page 58. SPDIF optical – The TV has an SPDIF optical connector that outputs a digitalaudio signal. To use the optical output, connect a TOSLINK optical cable from theamplifier to the Optical or SPDIF connector on the TV. You also must:o Select the appropriate setting under Settings > Audio > Digital audio out, as explainedin “Changing the audio mode” on page 56.Controlling other devices through CECConsumer Electronics Control (CEC) enables your TCL • Roku TV and other CEC-compatible homeentertainment components to control one other in various ways. First, the CEC-compatible devices must“discover” one another and report their capabilities. After this, one device can control anotheraccording to the features you enable. For example, playing a disc on a Blu-ray player could switch the TVto the Blu-ray player’s input. Or, powering off the TV could also power off the Blu-ray player and thehome theater receiver.Discovering connected CEC devicesTo discover CEC devices:1. Make sure that your CEC-compatible components are connected to the TV with a suitable high-speed HDMI cable that supports HDMI ARC and CEC control.2. Turn on each component and make sure all components have CEC enabled.Tip: Some manufacturers have their own branded names for CEC functionality, so you mightneed to read the product documentation to correctly identify the CEC features of the device.