What is S/PDIF connect and Digital Audio Out
These outputs have been developed jointly by Sony and Philips for use in televisions and other audio devices. They are used to transmit audio from a television, for example, to external acoustics.
You can stream audio in stereo without compression. Or you can output sound formats 5.1, 7.1, in compressed form. Sound can be output using an electric digital signal or optical.
Digital Audio Out
digital audio out – This output takes the form of the usual RCA connector. The devices are interconnected by a coaxial cable, the sound is transmitted digitally using special protocols. The approximate maximum cable length between devices is about 10 meters. But it also depends on the quality of the materials used and the manufacture of the cable.
Optical S/PDIF (spdif full form Sony/Philips Digital Interface Format)
optical S/PDIF (Sony/Philips Digital Interface Format) – in this case, the sound is transmitted using a laser over an optical cable between the devices. The power of the transmitted optical signal is such that the maximum possible distance between devices is also about 10 meters.
It can be said that these two outputs are the same in terms of the quality of the transmitted signal, since the audio signal is immediately transmitted digitally, bypassing its processing into an analog signal. The analog signal is more susceptible to any distortion and more attenuated at high frequencies. Similar connections, quite a lot the same HDMI supports sound transmission. And the latest versions of HDMI support Dolby formats.