SP/DIF questions

[ThreeFingersOfLove]

Italo,

I was browsing the H-8000 FW manual for some information and on page 11 it says:

"Eventide does not recommend the use of S/PDIF at sample rates above 48kHz."

and then below one paragraph it says:

"The input circuitry for S/P DIF 3/4 allows better performance than S/P DIF 1/2 and will operate better at 96kHz or with long leads."

I am a bit confused: SP/DIF on 3/4 sounds better at 96 KHz or with long leads BUT Eventide does not recommend going above 48 KHz with SP/DIF? Does this refer to the SP/DIF over RCA and/or SP/DIF over the optical ins/outs?

Also is it possible to mix different sampling rates, i.e. an algorithm running at 96 KHz on DSP A and a different algorithm running at 48 KHz on DSP B?

Thanks in advance.
Yannis

[IDeangelis]

 Yannis

S/Pdif is simply a consumer protocol generally not recommended for pro_audio high sampling rates. AES-EBU is the way to go for 96. But if you really must use 96, then the S/Pdif 3/4 has a better performance in terms of clocking stability.

You can't mix different sampling rates. One clock rate for the whole unit.

best

I 

[ThreeFingersOfLove]

Hi Italo,

I know about the SP/DIF being a consumer digital protocol. I just wanted to clarify between "doesn't recommend because problems may appear" and "it won't work at all".

Also, I think I have read someplace that there is something called SRC. Is this used to change the sample rate prior to hitting the DSPs?

In the manual, it is also mentioned AES11-AES18. Are these the 8 AES/EBU signals coming from the DB-25 connectors?

Is there a way to output a signal from analog outs 1, 2 or 3, 4 without it appearing at the AES/EBU outputs? From the manual, I figured that the analog outputs and SP/DIF outputs derive their signal from the AES/EBU. I was just wondering whether there is a workaround, maybe a custom routing?

Why don't you make available the Routing application to all people so we can see some possible configurations? I have the Routing app for the H-8000 and Orville, but they differ from the H-8000 FW.

Thanks,
Yannis.

[IDeangelis]

S/Pdif will work…but don't expect the best clock sync from it.

 Routing is actually available for the H8000Fw. Check the Eventide website, H8000Fw page> Software Updates.

Yes, AES 188 thru 18 are the ones wired thru the DB25.

I don't know where exactly the SRC is applied but I would think it's before the DSP so that it's not taking resources away from FX.

The question about analog and aes is a bit vague as routings need to be considered in relation to DSPs I/Os. If you want a DSP coming out of analog and the other out of AES-EBU, you can. The concept is about configuring MAIN inputs and outputs first. You will always have 8 of them and you need to decide which type og protocols they use, as there are a few dozens I/Os. The Routing flexibility is very open, with a few limitations described in the manual.

best

I 

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