Ask LH: Can You Explain S/PDIF Connectors To Me?

Ask LH: Can You Explain S/PDIF Connectors To Me?

Dear Lifehacker, What is the difference between Toslink and S/PDIF connections? And are there any decent converters that can convert S/PDIF to coaxial that won’t cost me an arm and a leg? Thanks, Not Quite an Audiophile

Dear NQAA,

S/PDIF is a type of digital audio cable format that stands for ‘Sony Philips digital interface’. It can be used with optical fiber connectors such as TOSlink which converts the S/PDIF signal to light. So in a nutshell, S/PDIF is the audio signal and TOSlink is the connector. S/PDIF can also be used with coaxial connectors (i.e. — RCA).

In terms of audio quality there’s really not much in it between optical and coaxial — some audiophiles argue that optical connections are superior but you’d be hard pressed telling the difference in most home theatre setups. Furthermore, optical cables are considered less sturdy than coaxial; bending or stepping on them can lead to permanent damage.

As to the second part of your question, there are plenty of Optical (Toslink) to RCA (SPDIF) Converters on the market that won’t break the bank. You can snap up brand-new models for as little as $15, although we can’t vouch for the quality of cheaper brands. Pay a visit to the usual shopping websites like eBay, Google Shopping and StaticIce to find yourself a suitable bargain.


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  • I’m pretty sure that as with everything “Digital”, quality of cable really doesn’t matter that much. I bought 5 el-cheapo TOSLINK optical cables from ebay for $5, and they work great with my system. I’m also using a normal RCA video cable as a SPDIF coax cable and it’s perfect as well. Don’t pay more than you have to!

    • Agreed, anything digital I buy off ebay and buy in bulk for future/friends. Bought 10 x 3 meter HDMI cables for less than $15 off ebay and something similar with audio cables.

    • I disagree. Quality of cable doesn’t affect quality of signal, yes. But poor quality gear just never ever lasts as long as decent quality gear.

      I’m not saying you have to buy Monster brand or whatever (you definitely shouldn’t) I’m just really sick of cheap cables that last less time than they took to get delivered.

  • The major difference between the two types of cable is that the Toslink is completely immune to interference.
    Have you every hard a weird noise in your speakers due to your mobile phone being placed nearby? That is what I’m talking about.
    If you have blast furnaces, industrial electrical motors, WiFi routers and access points, or high voltage powerlines nearby, then toslink is the way to go.
    Otherwise, just choose on price.
    I run toslink wherever I can because all of my audio cables coincidentally are right next to wireless access points, and the cost isn’t a big concern for me.

    • Ground loops.
      When you have 2 electrical items, both with a connection to mains ground AND to each other, you create a “loop” which can pick up noise. The data signal SHOULD not be affected by this interference: if it did, you’d get zero audio vs degraded audio in an analog setup.
      The actual data is represented by clock edges- if the signal flips from low to high (or high to low) halfway through a clock period, that’s a logic “one”. If it only changes at the end of clock period, that’s “zero”. If it never changes, you have faulty equipment or a broken cable.

      Homebrew stuff, with poorly designed power supplies, might not like your connection to earth via the audio cable. Optical cables provide excellent electrical isolation.

  • My TV has an SPDIF connector and I want to connect it to my home theatre which has TOSLINK. May I know the possible options how I can achieve that, please??

  • As per the article, search Ebay (or the free-ship China stores like buyincoins, tmart, dx ,tinydeal etc.) for an ‘spdif to toslink’ adapter. You can use a standard RCA (video, not audio) cable to connect to the adapter and then use a (cheap is fine) toslink optical cable to connect to your amp.

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