Digital Coaxial audio cable: test

[sdiesel77]

Hi Guys,

I'm currently wondering if I should change or not my cable between my squeezebox and my DAC.
It's currently an optical cable (TCI Coral Digital) and was wondering if it could be better if I put a coaxial instead.

I don't have any good optical cable at the moment with which I could do the test and was wondering if I could borrow one to one of you guys just for a couple of days :p

Thanks in advance :)

[HiFiFan]

My understanding is that TosLink (optical) is the worst signal path. I have read that the preferred order is usually

AES (110 ohm)
S/PDIF RCA/BNC (75 ohm)
Optical

[Ken Moreland]

Hi, I have a Wireworld Supernova 6 Toslink http://www.thecableco.com/Product/Supernova-6-Toslink and a LAT International DI 20 Mk2 RCA coax http://www.latinternational.com/index.p ... %20ii.html , both doing nothing and you're welcome to borrow and compare . They are both 0.5m long.
KM

[DaveF]

My understanding is that TosLink (optical) is the worst signal path.

This simply isnt true at all. Nothing wrong with a TosLink cable as a medium for transmitting digital data as long as its built properly. What matters is the implementation in the receiving device (and transmitter to some extent) in doing the optical to electrical conversion.

[HiFiFan]

Perhaps I should have been clearer I wasn't talking about the cable but the entire signal path. I agree that there is nothing fundamentally wrong with optical and in fact we use fibre heavily throughout our observatory. In terms of typical consumer audio implementations a number of articles I have read stated that typical Toslink implementations tend to have more Jitter (of course this may not be true). I'll be interested to hear the results of the posters tests to see if any discernible difference was heard between the coax and optical paths.

[sdiesel77]

Hey Ken,

Thanks a lot! I'd love to try the LAT International DI 20 Mk2 RCA coax!

pm sent :)

[DaveF]

In terms of typical consumer audio implementations a number of articles I have read stated that typical Toslink implementations tend to have more Jitter (of course this may not be true).

That can be true depending on the type of fibre and what the transmitter is doing. What you can get is 'dispersion' within the fibre which results in a smearing affect on the data bit edges, basically jitter. It's caused by the transmitter transmitting at wavelengths that approximate to the desired wavelength, ie the wavelength is wandering about a tiny amount. Generally the photodiode(which converts the optical to electrical) should retime and regenerate the digital stream anyway. As with any implementation there are correct ways and poor ways of doing this.

[Fran]

OT: DaveF - I've often read how toslink is great as there is no direct electrical connection between components - so great for a PC to dac in theory due to the separation of grounds. However, its almost never used - is this due to the complication of the receivers and transmitters etc?

[sdiesel77]

Test completed! :-)

I had the pleasure to meet our friend Ken this morning, really cool guy !

IMO, I couldn t hear any major difference between my current tci optical cable, a wireworld glass optical cable and a LAT coax RCA.

In a certain way it's reassuring me that my current cable is not that bad after all :-)

[Ken Moreland]

Steph, enjoyed our visit this morning, great apartment and very impressed with the convenience and flexibility of the Squeezebox touch. Lots of excellent options and a great amp and speakers too. You could probably keep it as is and make an additional link from your laptop via Jplay to your Dacmagic for a less convenient option. Anyhoo, thanks for the welcome and good to meet you both.
KM