• Registered: 2011-07-21
  • Posts: 49

Topic: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

Hi everyone

My setup is as follows:
8 Channels API Mic-Pre Line into Octamic II via ADAT to Octamic XTC via Madi to UFX+.
Octamix II is on Madi Stream 1-8, XTC on Madi Stream 9-16.
Lynx Aurora 16 via ADAT to UFX+. Slave via ADAT.
UFX+ is the master, clocking at 48k seems OK.
Delay compensation for Madi ID1 is on Auto in the XTC.

Recording as follows:
8 Mics into the APIs, arriving at Madi 1-8.
1 Line Output from the APIs is multed at Patchbay, going through a Distressor and coming back in via Lynx into ADAT 1.

The signal from the Distressor via ADAT comes in 31 Samples early compared to the Madi stream.
Is there any way to compensate for this negative delay?

Best,
Frank

Happy Fireface UFX+, Octamic XTC and M-32 Pro user.
http://www.stoersender-studio.ch

2 Reply by MC

  • MC
  • MC
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  • Registered: 2007-04-06
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Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

What happens if you disable the delay compensation?

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2011-07-21
  • Posts: 49

Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

Hi and thanx for the fast response!

My test setup is a mono signal out UFX+ Line 3/4.
If two inputs are on the same device (Lynx, Octamic II, Octamic XTC or Line Ins on the UFX+) they null.
I can't get any pair of inputs from 2 different devices to null (checked volume etc.).
Tried it both with and without delay compensation on the XTC, it doesn't make a difference.

Happy Fireface UFX+, Octamic XTC and M-32 Pro user.
http://www.stoersender-studio.ch

4 Reply by MC

  • MC
  • MC
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  • Registered: 2007-04-06
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Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

Of course they can't 'null' because every converter has a different delay. That is no problem unless you put a stereo signal on two converters (who would do that?). The question is if disabling Delay Compensation will reduce the error from 31 samples to a few samples, which can then be ignored for normal applications.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2011-07-21
  • Posts: 49

Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

MC wrote:

That is no problem unless you put a stereo signal on two converters (who would do that?). The question is if disabling Delay Compensation will reduce the error from 31 samples to a few samples, which can then be ignored for normal applications.

And unless someone maxes out Inputs with Mic Signals on one device and wants to employ parallel processing on the Signal via another converter. The slightest delay will render any attempt of live monitoring with the parallel processing useless (I just correct the delay later in the daw).

The delay seems to happen inside the XTC as it converts the Adat Ins to the Madi stream.
I guess it would be best to invest in 32ch of the same AD/DA converter, going into Madi on the UFX+ then.

Happy Fireface UFX+, Octamic XTC and M-32 Pro user.
http://www.stoersender-studio.ch
  • vinark
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Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

I am not 100% sure about this but if going in the AD with a mic signal and then out and in again with the parallel processing, the parallel processing will always be delayed even on one converter. This only works on analogue. Or if a outboard mic preamp sends both to the AD and the external processor. But it is easy to try just do it on one converter and see if you get the results you need.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632
  • Registered: 2011-07-21
  • Posts: 49

Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

vinark wrote:

I am not 100% sure about this but if going in the AD with a mic signal and then out and in again with the parallel processing, the parallel processing will always be delayed even on one converter. This only works on analogue. Or if a outboard mic preamp sends both to the AD and the external processor. But it is easy to try just do it on one converter and see if you get the results you need.

The signal gets multed line level at the patch bay. If I try it on 2 channels of the same converter it works as it should.

Happy Fireface UFX+, Octamic XTC and M-32 Pro user.
http://www.stoersender-studio.ch
  • vinark
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Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

Ah ok that is as expected. Then indeed it is a choice of getting identical converters (or a 32 channel one, like the M-32AD pro) if you don't want to swap. You could also of course configure your setup to have 1 or 2 spares on every AD for just these occasions.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632
  • Registered: 2011-07-21
  • Posts: 49

Re: Adat/MADI Conversion Delay on UFX+/Octamic XTC/Octamic II

Just did a test with screenshot:
https://imgur.com/a/5LXlzvv

Track "Madi 1" is coming back via Octamic II --Adat--> Octamic XTC --Madi--> UFX+.
Track "Madi 9" is coming back via Octamic XTC --Madi--> UFX+.
Track "Adat" is coming back via Lynx Aurora 16 --Adat--> UFX+.
Track "Line1" is coming back directly into the UFX+.


Exact same result with Auto Delay Comp. on XTC On/Off.

At least it's an interesting problem to have.

Happy Fireface UFX+, Octamic XTC and M-32 Pro user.
http://www.stoersender-studio.ch