PCM (pulse-code modulation) is a type of digital audio signal common with high-definition television broadcasts and audio-encoded on multimedia discs such as Blu-Ray. Some Sony audio video receiver models are equipped with a PCM 48 setting to take advantage of the full sonic range that PCM can deliver on Blu-Ray discs or TV shows presented in high definition. However, the PCM setting can cause audio problems when listening to programs presented in standard definition. If the Sony receiver locks in PCM 48 mode, it may be due to a compatibility issue with different connecting cables.
Instructions
1. Turn off the Sony receiver and all components connected to it, then switch on the equipment.
2. Press the "PCM" button on the Sony remote control to switch out of PCM mode. This will display on the LCD screen on the front of the receiver.
3. Play an audio source through the Sony. If it switches back to PCM 48 mode, the likely reason is a cable compatibility issue.
4. Check the back of the receiver, the television and the source signal (such as a cable or satellite receiver box) to determine which types of cables are interconnecting with the components. On a high definition system, a six-sided HDMI (high definition media interface) cable will likely be used to connect the source signal to the TV or the receiver. An optical cable, which resembles a telephone line and plug, might be used as a separate connection from the TV to the Sony.
5. Disconnect the optical cable from the back of the Sony receiver by pulling the plug straight out. Connect a standard stereo cable from a free set of input jacks on the Sony to the component, such as a TV, which is hooked up to the other end of the optical cable. The white and red plugs on the stereo cable connect to the matching colors on the left and right audio jacks.
6. Press the "PCM" button on the remote once more to switch out of PCM mode, then retest the sound on the Sony receiver.
7. Switch out the stereo cable with an optical cable when listening to all-digital sources.
Tags: optical cable, Sony receiver, high definition, stereo cable, cable from
