TECH TIPS - SPDIF CONNECTIONS EXPLAINED

S/PDIF (Sony/Phillips Digital Interface) is a consumer audio connection standard for transmitting high-quality digital audio. It is primarily used for connecting home cinema (home theatre) systems, Hi-Fi, games consoles, set top boxes, computers, and other consumer entertainment devices. S/PDIF can carry two channels of uncompressed PCM audio or compressed 5.1/7.1 surround sound such as Dolby Digital or DTS audio. The S/PDIF interface and the associated connectors can be implemented in two different ways “optical and coaxial”


OPTICAL 

 This implementation uses fibre optic cables that can be equipped with two different types of connectors - TOSLINK  and Mini Optical. Advantages of fibre optic as a transmission medium are immunity to electrical RF interference and ground loops, and, when using quality cable construction and materials, low signal attenuation meaning distances of up to 50m are supported (for example with Lindy Gold TOSLINK S/PDIF cable).

TOSLINK (abbreviated from Toshiba Link) is the most common connector type. You will typically find it on many larger consumer AV and Hi-Fi products such as amplifiers and set top boxes.

Mini-TOSLINK connectors are sometimes called MiniPlug or Mini Optical but they all refer to the same connector.

Adapters can be used to convert a TOSLINK connector to Mini-TOSLINK. The mini-optical connector is typically used on audio devices, such as the Google Chromecast Audio, and laptops. Some laptops feature a combined Mini TOSLINK / 3.5mm audio socket as these connectors are physically very similar in size. Lindy Optical Audio (S/PDIF) cables are ideal for home cinema and audio devices in professional installations. 


COAXIAL

This version of the S/PDIF interface requires the use of RCA phono connectors and 75 Ohm coaxial cable. To comply with the specifications and operating standards of S/PDIF It is important that 75 Ohm cable is used rather than ‘standard’ phono cables which look physically the same. Without getting too technical, this is because it is important that the two devices connected by the cable must have matching impedances otherwise the interface may not function correctly and you may experience drop outs, audio jitter or no sound at all. 75 Ohm S/PDIF Coax cable can usually be distinguished from other ‘analogue’ phono / RCA cables by orange colour coding on the outside and / or inner connector housing.

To browse the range of Lindy S/PDIF optical and coaxial cables, click here.