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Anonymous (not verified)
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Can an audio cable be used for coaxial digital connection?

This is a very novice question. I'm running an ordinary audio cable from my sound card to my receiver's digital input. It sounds pretty good to me but should I be using a special coaxial cable for this? If so, what's a good low cost one? I've haven't seen this discussed anywhere so I'm enquiring now.

Thanks for any enlightenment on this.

ampnut
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Re: Can an audio cable be used for coaxial digital connection?

An 'orinary' audio cable will certainly work, as long as the cable length is not toooo long.

However, to my ears, a 'digital' cable sounds better.

How much beter, will depend on the quality of the equipment used, the room, and ofcourse, your mind.

I dont want to ventilate on whether Cable differences are audible... to me they are.

However, a bit of simple theory:

'Ordinary Cables' do not have any specific 'impedance'

Digital audio sending & receiving ports, as well as cables, have a 75 Ohms impendance.

One way to understand the relevance of this impedance is that the Voltage in these sections ( In Volts ) is 75 times the current ( in Amperes ).

Hence a 1 Volt signal put out by the digital sending port will also push out 1/75 amperes ( 13.33 milli Amps ) of current.

The 75 Ohm cable now has to carry this Exactly same ratio of voltage & current to the Digital receiving port, which in turn will demand the same Voltage to current ratio of 75.

Any excess Voltage or current will be 'bounced' back to the input, creating an echo or a 'standing wave.'

Ideally there should be no 'echo' so that 100% signal transfer takes place. This is possible only if the proper impedance (75 ohms ) cable is used.

The Cable impedance of 75 ohms is created by the dimensions of the centre conductor, the diameter of the braid, and the dielectric material used in the coaxial cable.

Editor
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Re: Can an audio cable be used for coaxial digital connection?


Quote:
I'm going into the city tomorrow so I can easily pick a digital cable.

You don't have to spend a lot of money. Pro-audio cable manufacturer Canare makes digital datalinks for around $30 that provide good baseline performance.

John Atkinson
Editor, Stereophile

FrankM
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Re: Can an audio cable be used for coaxial digital connection?

A bit off topic:

Out of necessity once I had to use Composite Video Cables to connect a CD player to a receiver (mid-fi stuff) at the lake house. I remember remarking how the CDs were more 'alive' than with RCA audio cables from home.

Jeff Wong
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Joined: Sep 6 2005 - 3:28am
Re: Can an audio cable be used for coaxial digital connection?

I've been curious about trying the opposite... I thought it would be interesting to use a pair of the beautifully constructed Illuminati Orchid AES/EBU digital cables between my preamp and amp.

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