S/PDIF to AES/EBU with 110ohm cable.

[completeluxury]

about if the aes is designed to work with a certain ohms or if 75 ohms cable is fine

[octaviars]

I am testing a Neutrik rca male to xlr male adaptor placed in the master and connected to the slave with my Taralabs xlr cable right now. Before I used the Crystal cable with a adaptor in the slave to xlr input. Right now l think I like the sound better with the xlr cable, maybe the Taralabs is better than the Crystal cable and not so much that it is xlr verses coax rca cable.
If I build a cable with Oyaide I dont really think it matters so much if I use 75 Ohm or 110 ohm cable more important is the contacts that they are of good quality.

[octaviars]

I knew I have seen this in another thread and today I found it.

So I asked Thierry how this could work then!

He says (which I didn't manage to read on the homepage) that when using the RCA--XLR link the linking cable should be 110 ohms and not 75!!! As the system will recognize the impedance of the cable. And this goes for all of us that would like to use the AES/EBU for a streaming input on the Master as well ie use a 110 ohm cable.
Connection is the 'semi-balanced' way as schematically showed on Devs homepage.

I told him about the Audioprana cables and the 75/110 ohm transformation. Thierry said it would not be a problem but less good as their own solution due to adding another transformer in the line of signal.

Strange that they do not mentioning this?

http://devialetchat.com/showthread.php?tid=484

[miro]

I just received the following reply from the Devialet support email.
However, it still does not answer whether coax or AES/EBU will sound better for the master-slave connection:


Dear Sir
Thank you for your message.
For short cable length between master and slave, impedance mismatch is absolutely not an issue.
XLR input has 110R input impedance
COAX input and output have 75R impedance
We generally use a 75R COAX cable plus a COAX to XLR adaptor located on the companion unit. This works very very fine, is rather inexpensive (110R cable is much more expensive) and allow cable length up to around 10 meters.

[completeluxury]

i get the feeling that they think it doesnt matter for sound quality either way. and it very well might not!

[octaviars]

I also got answer today from Devialet.

Dear Sir,
Thank you for your message.
In our daisy chain topology, impedance mismatch is absolutely not an issue at all. Our units are immune to it.
We prefer to adapt the impedance at the master's output, so we definitely recommend 75R coax cable plus a coax to xlr adaptor located on the companion unit. This works very well and is rather inexpensive. 110R cable is fine too but is more expensive.
Best regards,

But this did not answer really my questions so I asked if there were any advantage to use a 110 ohm cable regardless of the cost.

Dear Fredrik,
The difference between the two is very slight so the end choice will depend on your personal preferences.
But really according to our experience, the 75ohm coax performs very well.

I think that they will not tell you what is the best solution, but I now know that you can go with ither cable directly to the xlr input on the slave.

[completeluxury]

i think that when it comes down to something like personal preference of the sound between 2 different interconnects they are probably wise to not give a definitive answer.

If both solutions will work but there is a slight sonic difference and they tell people to go with a particular method and the person doesnt like it then there is the opportunity to badmouth dev for giving them the wrong advice etc. better to steer clear of the whole thing!

[NickB]

i think that when it comes down to something like personal preference of the sound between 2 different interconnects they are probably wise to not give a definitive answer.

If both solutions will work but there is a slight sonic difference and they tell people to go with a particular method and the person doesnt like it then there is the opportunity to badmouth dev for giving them the wrong advice etc. better to steer clear of the whole thing!

On this forum - surely not

[completeluxury]

i was talking in absolute generalities not just this forum... but some people do have their moments

[Mikeeo]

I also got answer today from Devialet.

Dear Sir,
Thank you for your message.
In our daisy chain topology, impedance mismatch is absolutely not an issue at all. Our units are immune to it.
We prefer to adapt the impedance at the master's output, so we definitely recommend 75R coax cable plus a coax to xlr adaptor located on the companion unit. This works very well and is rather inexpensive. 110R cable is fine too but is more expensive.
Best regards,

But this did not answer really my questions so I asked if there were any advantage to use a 110 ohm cable regardless of the cost.

Dear Fredrik,
The difference between the two is very slight so the end choice will depend on your personal preferences.
But really according to our experience, the 75ohm coax performs very well.

I think that they will not tell you what is the best solution, but I now know that you can go with ither cable directly to the xlr input on the slave.

Fredrik,

Many moons ago Thierry said that it would be beneficial to use their suggested hybrid set up for a connector cable between mono units as on display on the homepage but I do not know if it is still there. However at the same time Thierry said that 110 ohm cable would be the best option and I quote him and myself from earlier forum input, "The input AES/EBU is 110 ohm and if using a 110 ohm cable the input will recognize this better than a 75  ohm cable", something like that was what Thierry told me. Anyway, now it seems like they say 75 ohm instead. In my opinion I think it does not matter as the output is supposed to be 75 ohm (I doubt it will be to a stable std as it is a female RCA) and the input is 110 ohm so some kind of mix I guess. Buy the way, making a hybrid cable ie RCA to XLR (AES/EBU) and not using adaptor will ripe sonic benefits. Some adaptors are only hybrid ie semi balanced with no transformer or there are the likes of Neutrik with built in 75/110 ohm conversion. Thierry advice against having another transformer in the signal line as the AES/EBU input is already transformer coupled.
So my take on this is, use what ever 110 or 75 ohm cable (easier with 75 as it is easier to connect to the XLR in a semi balanced way), apply good connectors and very good soldering skills. Or you could go ahead and order a Cabledyne silver coax 75 ohm in semi configured wiring ie RCA to XLR.

As we live pretty close to each other you could come and pick up my Cabledyne to try out in your system while I am away during July.

/Mike