Hi,

I'd like peoples recomendations on SPDIF to AES Convertors. I'm not looking with a particular budget in mind just want recomendations of solid products.

Also interested in running AES for 130 meters. I know that the maxium is supposed to be 100 but am curious to see if anyone has managed to run it further, sucessfully and reliably?

Thanks

Well the BXF and BXM from Canford will do the impedance matching, if you're looking at converting between balanced and unbalanced, even if they do seem spectacularly overpriced. Then you just possibly have the different channel status bits to deal with, see Wikipedia for details. Although I believe we use Edirol MA-15D speakers with standard AES in via the SPDIF port with no issues.

As for the distance, I'd imagine we run it further, but I couldn't tell you if its balanced or unbalanced if we do.

Someone with more hands on experience can probably give you more information and confirm my vague memories. Although I imagine the choice of balanced (XLR3) or unbalanced (BNC) will affect things a certain amount.

Essentially the SPDIF interface (unbalanced phono plug or TOSLINK optical) are consumer formats - as found on CD and DVD players amongst other items. Professional equipment uses an (almost) identical data format - but uses different connectors, normally balanced XLR, or unbalanced BNC. These interfaces are defined in AES and EBU standards - full information can be found on the Web.

There are differences in the level and impedance of the various interfaces (as well as balanced or unbalanced working) - but it is fairly easy to interconnect between them if desired with simple passive convertors.

Distance working is an interesting subject - one that I am currently researching, with the distance for reliable (error free) working depending on the type of cable used and the sample rate being transmitted. Dedicated cables are available from Belden and VDC Trading for example - but good results can be obtained with balanced working on cheap Cat 5 type twisted pair cable - over quite long distances, especially at 48K sample rate.

I am very interested to hear of other applications and experiences......

Hi Waster

I have most of the answers for you.

SPDIF and AES/EBU are basically the same. There is an impedence and level change between the two. I tasked Dan Appleb y (an SFL employee and reader here) to make me a convertor for my own kit which he did. If you ask him he will tell you. Its just a bunch of resistors. Email dan@sflgroup.co.uk which shouldhelp if he does not see this. He is out on gigs for a few weeks yet so be patient if you cannot find the stuff yourself.

The other bit I will give you!

AES/EBU over balanced lines (XLR) turns into bobins beyond 100M, if you do it with 110Ohm "digital" twisted pair it's no better. Trust me I know ( http://www.sflgroup.co.uk/index.php?option...&Itemid=163 ) The (cheap) answer is to use Neutrik convertors ( http://www.neutrik.com/fl/en/audio/210_157...-FX_detail.aspx ) these take your 110 ohm balanced to 75Ohm coax which you run on coax before turning back to 110 at the other end. This is good for 300M.

Cheers

Mark

Thanks for the replies, especially the one from mark. Great info! I will email your man and wait patiently.

I do alot of work as systems engineer at large dance music events. I was after a way to take the digital output of a pioneer djm800 mixer (to which I have all the pioneer cdj's connected digitally) and get it into my xta's. Therefore keeping everything digital right up to the amps.

As for the long AES runs a church install I am involved with is looking at having a marantz solidstate recorder and cd burner installed in their media suite which is about 130m away (in cable tray runs etc) from their sound desk. I wanted to take advantage of staying digital and keeping the recorders at foh isn't something they want to do ideally.

Sorry to sound like a maniac about staying digital but I really beleive in the minimum processing necessary in a signal path and also once you go digital stay digital until the amps etc!

Thanks again for the advice.


p.s. (mark pm with your price for those neutrik adapters if you want)

Judging from Mark's reply it sounds like you need to stick with the wired spdif cabling for long distances as wired spdif is already 75 ohm co-axial. The important thing with coaxial cable is the cable quality - you will need decent quality cable to achieve the 300m that Mark talks about.

Cheers

James.