Optical or Coax?

Posted by: ChrisG on 28 August 2016

Just setting up my UnitiQute2, I'm also using a Sonos Connect for Spotify and my existing music library, (when listening multiform) is it best to use an optical or coax cable between the Qute and Sonos, I have a QED Performance Graphite optical cable at present but the connector doesn't seem too positive't in the socket both at the Qute and Sonos end?

Are there any recommendations, not too expensive, for either optical or coax cable that fit and perform well?

Best

Chris

Posted on: 29 August 2016 by Mike-B

Optical connections tend to have a wobble feel about them, cheap ones are a bit more wobbly than others; but remember it not making contact as does a RCA or BNC on a coax, its just bringing the light to/from the cable close to the sensors.

QED have a new optical "cable" (I think) called Reference with the fibre stands made of a quality quartz glass rather than the plastic than many are made with. Its good for 24-bit & 192kHz, which most optical cables won't go to, & although that will not be required with the Sonos it is indicative of the cables quality.

Posted on: 29 August 2016 by Mayor West

I was asking this in another thread recently and was advised that coax is better. I also saw on the Chord Co website in the FAQ that coax is suggested to provide better sound in most cases.

I'm currently using a Chord C-Digital coax cable at £35 which is actually really good but I'm very tempted to try something a bit higher up the range.

Posted on: 29 August 2016 by Adam Zielinski

Optical cable has one benefit - it provides a perfect galvanic isolation between the two devices.
So if you encounter hums or ground loop hums with a coaxial connection, you can swap to an optical one.

In an ideal world, coaxial is preferable for it's sound quality.

Posted on: 29 August 2016 by ChrisG

Thanks for all the help, I'll try a coax lead as well. Would the "Signal Ground Switch" on the Unitqute help with any hum if experienced with coax lead?

Chris

Posted on: 29 August 2016 by Adam Zielinski

It may. Just test it.

Posted on: 31 August 2016 by Huge

You'll get a better result from your existing music library if you connect the UQ2 using wired Ethernet and UPnP.

Posted on: 31 August 2016 by ChrisG

Huge

The Qute will be connected via wired ethernet and Asset UPnP, the optical/coax will be used solely for the Sonos connect input on the Qute when all other 6 zones are playing multiroom.

Posted on: 31 August 2016 by Huge

Ah, now that makes sense!

With respect to mains earth hum loops, the Sonos Connect has a 2 pin mains connection so cannot itself be earthed, however it's Ethernet ports have metal shielding and so might connect the audio to earth through the Ethernet shield IF you use shielded Ethernet cables. If your Ethernet cables are UTP (i.e. unshielded with plastic connectors at each end), then using a digital coax cable won't change your current earthing arrangements.

The usual rule applies: the audio path should be connected to earth at one place and only at one place.