[vvs_75]

I need to make cable to connect my transport / coax to DAC / 110 Ohm AES/EBU XLR.

In theory I need to use impedance transformer to mach 110 to 75 ohm impedances but As far as I understand you need one if you only running long cable. My cable will be max 3 feet.

I’ve done some reading a while ago and some people saying that even on short run the transformer still make a difference in SQ.

I am thinking to skip impedance transformer and make cable like this one:

So do you guys using impedance transformer in your source or not?


Thanks!

 

[grawk]

aes/ebu and spdif aren't the same format, so unless your aes/ebu port on your dac speaks spdif as well, you won't get the results you're looking for. As to impedance, it depends on the hardware. Sometimes it matters, sometimes it doesn't.

 

[vvs_75]

here is my source/DAC:

http://laurenstephens.net/uploads/449f43cc52.pdf

Thanks Grawk!

 

[grawk]

Judging from that, I'd say it won't work with spdif. But that if you can send it aes, it's probably relatively immune to impedance mismatch, with the transformer on input.

 

[vvs_75]

So I need to use impedance transformer like this one?

Neutrik - Audio - AES/EBU Impedance Transformer - NADITBNC-M

The problem is that they have BNC input. So I need spdif to BNC addapter to connect it to the transformer.

 

[grawk]

No. You need a transport that outputs AES or a dac that decodes SPDIF. They're not the same.

 

[vvs_75]

Take a look at this link:

Hydrogenaudio Forums > RCA SPDIF to AES/EBU (XLR) Converter

some peole still believe its ok just to use the impedance transformer.

 

[grawk]

It does work sometimes, if the device talks both. Can't hurt to try, but it won't be impedance that stops you if it fails.

 

[error401]

Quote:

Originally Posted by grawk /img/forum/go_quote.gif No. You need a transport that outputs AES or a dac that decodes SPDIF. They're not the same.

For the most part they are. The on-the-wire data format is the same. The differences are in physical medium and a couple meta-fields in the data format. In the vast majority of cases it should work fine.

There's a level converter schematic here epanorama.net/S/PDIF Interface

 

[grawk]

I can tell you in reality, they're different. I've fed spdif to aes and aes to spdif, and some converters like it and some don't. The ones that do usually have a way to say you're sending spdif or aes.

 

[vvs_75]

Look like I found solution! Aardvark S/PDIF to AES/EBU
The Company gone and adapter DISCONTINUED but it’s still possible to find one.


The option is a pair of adapters that fit onto the Electrical S/PDIF (RCA) I/O on the Aark24 breakout box. These adapters effortlessly convert incoming and outgoing stereo S/PDIF digital audio to stereo AES/EBU digital audio!

Thanks to everybody!