Digital Sample Rates

[tacman77]

I had connected my Eclipse to my 1820m via S/Pdif running at 48k with no problems for quite some time.

 I recently started running at 88.2k. I switched to ADAT because I was thinking that S/Pdif is limited to 48k but some have told me that isn't true now days.

 So I have have the clock on the Eclipse set to ADAT and the Eclipse front panel shows that the sample rate is 44.1. Seems to be working fine but the eclipse isn't really running at 88.2, is it?

Is this normal because of the way ADAT has to do higher sample rates?

I thought about getting a  BNC cable and trying word clock…

Is anyone using the Eclipse with word clock to set the timing of their DAW?
Interested in trying that.

Any help/info appreciated

Thanks 

[nickrose]

 S/PDIF is not limited to 48kHz. But, because of its reduced electrical specifications, we don't recommend its use at higher rates.

ADAT, on the other hand, IS limited to 48kHz. There is a higher frequency variant known as S-MUX, that will operate at higher rates, but with half the number of channels. This format is not supported by Eclipse.

If you are working with a DAW, Wordclock is probably the way to go. Depends on your hardware…

[tacman77]

I ordered a BNC cable. So when that comes I can use S/Pdif coax digital with wordclock @ 88.2k?

I tried choosing optical as the digital in but it says sample rate too high, I tried sending both S/Pdif and AES format optical.

 Strange that ADAT works at 44.1. It  must be going through a sample rate conversion somewhere because I'm recording at 88.2

I'm looking at a RME HDSP 9632 which has an AES-EBU XLR breakout option.

I could use mic cables to plug that in?

Thanks 

[IDeangelis]

 Tacman

as adviced by Nick, S/Pdif is not adviced for sample rates higher than 48 KHz.

You may try clocking w/BNC cable.

Using AES-EBU is highly recommended…and NO, don't use Mic cables. They may work at lower sample rates but won't at higher. In any case is a bad choice.

best

I

[nickrose]

 Italo is of course correct.

Interestingly, you can often get away with feeding 88.2k into 44.1k (or 96k into 48k). There will be a certain amount of bad stuff generated (aliasing) but it will usually be too high (frequency) or masked by the program material. Serious professionals would not rely on this, however.

[tacman77]

So let me see if I have this right:

The only way to get high sample rate I/O with the eclipse is the AES XLR connections and then I still need to have word clock.

Or word clock is optional?

Thanks 

[IDeangelis]

 You may  or may not have a good connection w/S/Pdif on highe sample rates, depending on different factors. As it's not a recommended standard for higher than 48KHz rates, AES/EBU, the pro standard, is adviced.

AES/EBU, like most digital protocols, supports clock sync pretty well.

Word Clock is adviced when:

-an audio DAW uses more than 3 digital devices

-clock instabilities are present. A dedicated W-C- device should keep everything properly clocked.

You can clock Eclipse on AES/EBU alone.

best

I

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