rca and digital coax

arossi · 25-05-2008, 15:26

What is the difference between rca leads and digital coax leads, is digital coax the same as optical but with different ends so you can use them to connect your dvd to an external amp? could someone explain please

RobAnt · 25-05-2008, 16:15

Digital coax is certainly not the same as Fibre Optic cable. One is metal, the other is transparent plastic. One carries electrical signals, the other a sort of super-super-super high speed flashing light or lights (not sure if there are several "channels" or not in that sense).

The only real difference between standard audio RCA leads and digital audio leads with RCA connectors is the number of ohms - 75 for digital - but most digital equipment seems to work just fine with standard RCA Phono leads. I have no idea what ohms are (a measure of impedence, perhaps), but I am sure standard, non-digital cables are different in that respect.

arossi · 25-05-2008, 16:22

Thanks for that, just thought that because i dont have an optical input on my surround sound i didnt know what would be the next best thing to use.
Thought that digital coax would have been better cause its digital, rcas are analogue are they not?

Nigel Goodwin · 25-05-2008, 16:41

Quote:

Originally Posted by arossi

Thanks for that, just thought that because i dont have an optical input on my surround sound i didnt know what would be the next best thing to use.
Thought that digital coax would have been better cause its digital, rcas are analogue are they not?

A single RCA (phono plug in the UK) is used for SPDIF - coaxial digital, which is the same signal as optical digital, but before it's converted to optical.

No such thing as digital coax, normal 'analogue' phono leads work just as well for SPDIF.

arossi · 25-05-2008, 16:50

This is where it has been confusing cause the website i was on has rca leads and it says they have digital coaxial audio leads

RobAnt · 25-05-2008, 16:56

For connecting digital sources via a coax connection only one wire with rca connectors at each end is required.

For connecting analogue sources, two (or more) rca connectors are needed.

[pedant mode on]

Of course, RCA connections are not the only way as some computer systems use 3.5mm jack plugs - and then you need a stereo jack plug at both ends for each pair of channels - OR a stereo jack plug to two RCA phono plugs for each pair of channels).

[/pendant]

So No, RCA Phono plugs are for both analogue and digital connections, in that sense. And yes, it is often a source of some confusion.

Nigel Goodwin · 25-05-2008, 16:56

Quote:

Originally Posted by arossi

This is where it has been confusing cause the website i was on has rca leads and it says they have digital coaxial audio leads

It's basically a con, however one advantage is that the colour of the plug should match the socket!

25-05-2008, 16:59

Quote:

Originally Posted by arossi

This is where it has been confusing cause the website i was on has rca leads and it says they have digital coaxial audio leads

If you are after a coaxial cable then try here........

http://www.audiovisualonline.co.uk/d...s/display.html

RCA is a connection type normally referred to as a phono connection, it can be used in the analogue or digital domain where it can carry video or audio, the distinction is in the cable name, i.e. coaxial, component, composite, these all use RCA (phono) connectors but are used in different areas, component/composite for video, coaxial for audio.

RobAnt · 25-05-2008, 17:04

Quote:

Originally Posted by Nigel Goodwin

A single RCA (phono plug in the UK)No such thing as digital coax, normal 'analogue' phono leads work just as well for SPDIF.

[pendant mode on]

Not strictly true. While normal leads do work, you will frequently find warnings to the effect that 75ohm coax is required.

[/pedant]

arossi · 25-05-2008, 17:07

Thanks for that, looks cheaper than the place i was on before, which is good cause ill need 2 of them

Nigel Goodwin · 26-05-2008, 11:36

Quote:

Originally Posted by RobAnt

[pendant mode on]

Not strictly true. While normal leads do work, you will frequently find warnings to the effect that 75ohm coax is required.

[/pedant]

Have you ever seen an SPDIF lead made using 75 ohm cable?, certainly it would be VERY rare.

26-05-2008, 11:55

Quote:

Originally Posted by Nigel Goodwin

Have you ever seen an SPDIF lead made using 75 ohm cable?, certainly it would be VERY rare.

Yes - Plenty of cable companies use 75ohm cable for SPDIF (coaxial) cables. Some use it for their analogue audio cables as well.

Ixos are one company that do.......

http://www.microdirect.co.uk/Product...ource=googleps

Aqvox are another.

http://www.aqvox.de/cable.html

Other examples here..

http://www.tvcables.co.uk/cgi-bin/tv.../se=leads.html

arossi · 26-05-2008, 12:08

Would i be better using leads from one of they websites then? going by what is being said that the digital coax is the way to go, so is rca becoming a thing of the past, why dont they sell digital coax as a pair as rca have have a pair?

26-05-2008, 12:27

Quote:

Originally Posted by arossi

Would i be better using leads from one of they websites then? going by what is being said that the digital coax is the way to go, so is rca becoming a thing of the past, why dont they sell digital coax as a pair as rca have have a pair?

You are getting confused between cable uses and terminations.

Digital coaxial is used for multichannel audio, it is used to connect a DVD player to an AV receiver, it is a single cable, it has RCA connections at each end, more commonly known as phono in the UK, RCA is just the name of the termination, the type of connection.

You would be looking for a pair of phono cables.

Saying this you could use 2x digital coaxial leads but there would be no real advantage in doing this. All you need is a pair of phonos that are well screened.

http://www.tvcables.co.uk/cgi-bin/tvcables/PGA4201.html

Nigel Goodwin · 26-05-2008, 16:44

Quote:

Originally Posted by TommyW

Yes - Plenty of cable companies use 75ohm cable for SPDIF (coaxial) cables. Some use it for their analogue audio cables as well.

Those all seem to be 'monster cable' type prices, supposedly offering superior sound quality over cheaper ones (which they don't).

Certainly using 75 ohm cables for analogue audio wouldn't improve anything, in fact the total opposite would be true, reducing the sound quality.

26-05-2008, 18:22

Quote:

Originally Posted by Nigel Goodwin

Those all seem to be 'monster cable' type prices, supposedly offering superior sound quality over cheaper ones (which they don't).

£7-49 Monster cable type prices?

http://www.tvcables.co.uk/cgi-bin/tv...nk-680051.html

Quote:

Originally Posted by Nigel Goodwin

Certainly using 75 ohm cables for analogue audio wouldn't improve anything, in fact the total opposite would be true, reducing the sound quality.

I wouldn't know what effect using 75 ohm cable would have on the audio, I only know that for digital coaxial using 75 ohm cable is very common, I'm guessing it's must have something to do with transmitting the data electrically, some will use this for their audio cables.

25-05-2008, 15:26	#1
arossi Forum Member Join Date: Mar 2008 Location: GLASGOW Posts: 22	rca and digital coax What is the difference between rca leads and digital coax leads, is digital coax the same as optical but with different ends so you can use them to connect your dvd to an external amp? could someone explain please

25-05-2008, 16:15	#2
RobAnt Forum Member Join Date: Jun 2003 Location: South West Posts: 10,218	Digital coax is certainly not the same as Fibre Optic cable. One is metal, the other is transparent plastic. One carries electrical signals, the other a sort of super-super-super high speed flashing light or lights (not sure if there are several "channels" or not in that sense). The only real difference between standard audio RCA leads and digital audio leads with RCA connectors is the number of ohms - 75 for digital - but most digital equipment seems to work just fine with standard RCA Phono leads. I have no idea what ohms are (a measure of impedence, perhaps), but I am sure standard, non-digital cables are different in that respect.

25-05-2008, 16:22	#3
arossi Forum Member Join Date: Mar 2008 Location: GLASGOW Posts: 22	Thanks for that, just thought that because i dont have an optical input on my surround sound i didnt know what would be the next best thing to use. Thought that digital coax would have been better cause its digital, rcas are analogue are they not?

25-05-2008, 16:41	#4
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by arossi Thanks for that, just thought that because i dont have an optical input on my surround sound i didnt know what would be the next best thing to use. Thought that digital coax would have been better cause its digital, rcas are analogue are they not? A single RCA (phono plug in the UK) is used for SPDIF - coaxial digital, which is the same signal as optical digital, but before it's converted to optical. No such thing as digital coax, normal 'analogue' phono leads work just as well for SPDIF.

25-05-2008, 16:50	#5
arossi Forum Member Join Date: Mar 2008 Location: GLASGOW Posts: 22	This is where it has been confusing cause the website i was on has rca leads and it says they have digital coaxial audio leads

25-05-2008, 16:56	#6
RobAnt Forum Member Join Date: Jun 2003 Location: South West Posts: 10,218	For connecting digital sources via a coax connection only one wire with rca connectors at each end is required. For connecting analogue sources, two (or more) rca connectors are needed. [pedant mode on] Of course, RCA connections are not the only way as some computer systems use 3.5mm jack plugs - and then you need a stereo jack plug at both ends for each pair of channels - OR a stereo jack plug to two RCA phono plugs for each pair of channels). [/pendant] So No, RCA Phono plugs are for both analogue and digital connections, in that sense. And yes, it is often a source of some confusion.

25-05-2008, 16:56	#7
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by arossi This is where it has been confusing cause the website i was on has rca leads and it says they have digital coaxial audio leads It's basically a con, however one advantage is that the colour of the plug should match the socket!

25-05-2008, 16:59	#8
TommyW Posts: n/a	Quote: Originally Posted by arossi This is where it has been confusing cause the website i was on has rca leads and it says they have digital coaxial audio leads If you are after a coaxial cable then try here........ http://www.audiovisualonline.co.uk/d...s/display.html RCA is a connection type normally referred to as a phono connection, it can be used in the analogue or digital domain where it can carry video or audio, the distinction is in the cable name, i.e. coaxial, component, composite, these all use RCA (phono) connectors but are used in different areas, component/composite for video, coaxial for audio.

25-05-2008, 17:04	#9
RobAnt Forum Member Join Date: Jun 2003 Location: South West Posts: 10,218	Quote: Originally Posted by Nigel Goodwin A single RCA (phono plug in the UK)No such thing as digital coax, normal 'analogue' phono leads work just as well for SPDIF. [pendant mode on] Not strictly true. While normal leads do work, you will frequently find warnings to the effect that 75ohm coax is required. [/pedant]

25-05-2008, 17:07	#10
arossi Forum Member Join Date: Mar 2008 Location: GLASGOW Posts: 22	Thanks for that, looks cheaper than the place i was on before, which is good cause ill need 2 of them

26-05-2008, 11:36	#11
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by RobAnt [pendant mode on] Not strictly true. While normal leads do work, you will frequently find warnings to the effect that 75ohm coax is required. [/pedant] Have you ever seen an SPDIF lead made using 75 ohm cable?, certainly it would be VERY rare.

26-05-2008, 11:55	#12
TommyW Posts: n/a	Quote: Originally Posted by Nigel Goodwin Have you ever seen an SPDIF lead made using 75 ohm cable?, certainly it would be VERY rare. Yes - Plenty of cable companies use 75ohm cable for SPDIF (coaxial) cables. Some use it for their analogue audio cables as well. Ixos are one company that do....... http://www.microdirect.co.uk/Product...ource=googleps Aqvox are another. http://www.aqvox.de/cable.html Other examples here.. http://www.tvcables.co.uk/cgi-bin/tv.../se=leads.html

26-05-2008, 12:08	#13
arossi Forum Member Join Date: Mar 2008 Location: GLASGOW Posts: 22	Would i be better using leads from one of they websites then? going by what is being said that the digital coax is the way to go, so is rca becoming a thing of the past, why dont they sell digital coax as a pair as rca have have a pair?

26-05-2008, 12:27	#14
TommyW Posts: n/a	Quote: Originally Posted by arossi Would i be better using leads from one of they websites then? going by what is being said that the digital coax is the way to go, so is rca becoming a thing of the past, why dont they sell digital coax as a pair as rca have have a pair? You are getting confused between cable uses and terminations. Digital coaxial is used for multichannel audio, it is used to connect a DVD player to an AV receiver, it is a single cable, it has RCA connections at each end, more commonly known as phono in the UK, RCA is just the name of the termination, the type of connection. You would be looking for a pair of phono cables. Saying this you could use 2x digital coaxial leads but there would be no real advantage in doing this. All you need is a pair of phonos that are well screened. http://www.tvcables.co.uk/cgi-bin/tvcables/PGA4201.html

26-05-2008, 16:44	#15
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by TommyW Yes - Plenty of cable companies use 75ohm cable for SPDIF (coaxial) cables. Some use it for their analogue audio cables as well. Those all seem to be 'monster cable' type prices, supposedly offering superior sound quality over cheaper ones (which they don't). Certainly using 75 ohm cables for analogue audio wouldn't improve anything, in fact the total opposite would be true, reducing the sound quality.

26-05-2008, 18:22	#16
TommyW Posts: n/a	Quote: Originally Posted by Nigel Goodwin Those all seem to be 'monster cable' type prices, supposedly offering superior sound quality over cheaper ones (which they don't). £7-49 Monster cable type prices? http://www.tvcables.co.uk/cgi-bin/tv...nk-680051.html Quote: Originally Posted by Nigel Goodwin Certainly using 75 ohm cables for analogue audio wouldn't improve anything, in fact the total opposite would be true, reducing the sound quality. I wouldn't know what effect using 75 ohm cable would have on the audio, I only know that for digital coaxial using 75 ohm cable is very common, I'm guessing it's must have something to do with transmitting the data electrically, some will use this for their audio cables.

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rca and digital coax