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75ohm cable vs RCA for transport to preamp

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Has anyone noticed a major difference in swapping between these types of cables ?

Transport = Shanling T80 CD player

Pre = Intergra 80.1

amp = Elecktra Theatron Power amp

I know the theories about greater bandwidth but just want some feedback

Going to try an A/B over the weekend between the standard concord RCA (Jaycar) and a Lenehan 75 ohm cable

Thanks Chewie

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Hi Chewie,

Most cheap coaxial cables intended for video are supposed to be 75 ohms impedance. Most of these have yellow RCA connectors fitted. Whilst they may work, many are rarely 75 ohms impedance. RCA connectors, by their physical construction (relationship of the diameter of the centre pin vs the outer sleeve) can't yeild a 75 ohm connector, which means that even if the cable between them is 75 ohms, the overall lead will be a compromise of the true 75 ohm impedance we ideally are seeking to maintain.

IME, if you have to use RCA connectors, buy those with a declared impedance as close to 75 ohms as possible. IIRC Canare market one that comes close by using a unique internal construction wich minimises the mismatch.

Crimped rather than soldered is generally accepted as better for digital in maintaining a constant impedance, thereby reducing signal reflections due to impedance mismatch.

It may turn out you can't hear any difference with the equipment you have, in which case you could save your money and use the cheaper interconnect in the interim until you upgrade sometime in the future where your gear may reveal a sonic difference. Having never heard the Lenehan 75 ohm cable, I can't comment from personal experience on how different it might sound compared to the cheapie Jaycar cable. IME using a true or close to true 75 ohn cable made from proper 75 ohm cable and using crimped connectors sounds better in my system than the cheapie all purpose cables intended for combined video and SPDIF applications.

You may have noticed that professional digital connections usually use BNC connectors for 75 ohm links, and AES/EBU links use 110 ohm balanced cable and XLR connectors.

Cheers,

Alan R.

Edited by Alan Rutlidge

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Thanks Alan

Jaycar are suppose to be 'decent' quality so Ill find out soon.....

Cheers chewie

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Usually not a good idea because the 75 ohm impedance of the digital cable creates much higher capacitance per foot than a good analog interconnect. You should be looking for less than 10pF/foot.

High capacitance puts a higher than necessary load on the DAC output drivers and forms a low-pass filter with the source resistance.

Steve N.

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Hi Chewie,

Most cheap coaxial cables intended for video are supposed to be 75 ohms impedance. Most of these have yellow RCA connectors fitted. Whilst they may work, many are rarely 75 ohms impedance. RCA connectors, by their physical construction (relationship of the diameter of the centre pin vs the outer sleeve) can't yeild a 75 ohm connector, which means that even if the cable between them is 75 ohms, the overall lead will be a compromise of the true 75 ohm impedance we ideally are seeking to maintain.

IME, if you have to use RCA connectors, buy those with a declared impedance as close to 75 ohms as possible. IIRC Canare market one that comes close by using a unique internal construction wich minimises the mismatch.

Crimped rather than soldered is generally accepted as better for digital in maintaining a constant impedance, thereby reducing signal reflections due to impedance mismatch.

It may turn out you can't hear any difference with the equipment you have, in which case you could save your money and use the cheaper interconnect in the interim until you upgrade sometime in the future where your gear may reveal a sonic difference. Having never heard the Lenehan 75 ohm cable, I can't comment from personal experience on how different it might sound compared to the cheapie Jaycar cable. IME using a true or close to true 75 ohn cable made from proper 75 ohm cable and using crimped connectors sounds better in my system than the cheapie all purpose cables intended for combined video and SPDIF applications.

You may have noticed that professional digital connections usually use BNC connectors for 75 ohm links, and AES/EBU links use 110 ohm balanced cable and XLR connectors.

Cheers,

Alan R.

I dont find the canare rca to be good for digital cables eti bulleit plugs for this termination work wonders.........

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Guest Muon

Usually not a good idea because the 75 ohm impedance of the digital cable creates much higher capacitance per foot than a good analog interconnect. You should be looking for less than 10pF/foot.

High capacitance puts a higher than necessary load on the DAC output drivers and forms a low-pass filter with the source resistance.

Steve N.

Hmm...

The cable I have now measures much higher than this (cheap 75ohm commercial cable), so I'll have to have a play making some new cables :)

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Hang on - how are you connecting the CD player to the pre-amp? Analog or digital?

If digital go with coax.

If analog I would go unshielded interconnect, not coaxial.

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I dont find the canare rca to be good for digital cables eti bulleit plugs for this termination work wonders.........

Interesting because the ETI bullet plug suggests that it isn't a 75 ohm connector. Do you use 75 ohm Coaxial cable?

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Yes digital connection from CD to Pre

Did the listening session on the weekend swapping between the Lenehan 75ohm cable and the regular concord RCA cable.

Obvious difference sound opens right up worth the extra $$

Chewie

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The choice then becomes obvious. Glad you found the cable you prefer Chewie. :)

Cheers,

Alan R.

Edited by Alan Rutlidge

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I dont find the canare rca to be good for digital cables eti bulleit plugs for this termination work wonders.........
Interesting because the ETI bullet plug suggests that it isn't a 75 ohm connector. Do you use 75 ohm Coaxial cable?
This article by Blue Jeans Cable may explain the Canare design philosophy - http://www.bluejeanscable.com/articles/75ohmrca.htm However, technology aside, if an ETI connector turns out to be better, who am I to argue the point? :)

Cheers,

Alan R.

Edited by Alan Rutlidge

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This article by Blue Jeans Cable may explain the Canare design philosophy - http://www.bluejeans...es/75ohmrca.htm However, technology aside, if an ETI connector turns out to be better, who am I to argue the point? :)

Cheers,

Alan R.

Agreed Alan. I am genuinely interested in what people are using. I started a thread on this topic in the cable and wire sub-forum.

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This article by Blue Jeans Cable may explain the Canare design philosophy - http://www.bluejeans...es/75ohmrca.htm However, technology aside, if an ETI connector turns out to be better, who am I to argue the point? :)

Cheers,

Alan R.

I can give you ademo if you would like mr.rutlidge

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I can give you ademo if you would like mr.rutlidge

Thanks Mario. I don't doubt you are more than satisfied with the ETI connector's performance and nothing in my reply IIRC implied it wasn't any good.

If you have extensively ear tested the two and found the ETI to be better, that's good enough for me. :)

Cheers,

Alan R.

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Interesting because the ETI bullet plug suggests that it isn't a 75 ohm connector. Do you use 75 ohm Coaxial cable?

Yes its a 75ohm coaxial cable just like lenehan ribbontek exactly the same cable tried many connectors in the days of spdif on the same cable.

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