• Registered: 2020-01-31
  • Posts: 2

Topic: MADI Router - Glitching Issues

Hi all,

I've got a problem and i've close to exhausted all ways to try and fix it within the current format. The problem is random clicks, and dropouts of audio.

I have a number of devices connected via a MADI router. Most are behaving nicely.

As far as I have troubleshooted, the source of the issue is between a Digico SD11 and the MADI Router.

Signal Path:
I'm sending main PA outputs out of the MADI output on the SD11 to the MADI Router via BNC MADI connections.
The MADI Router then outputs this full stream to an Outline Newton system processor via Optical MADI connections.

All devices are clocking off Word Clock, generated by the Outline Newton.

Faults:
With MADI Receiver set to 'Bypass', I get all sorts of random clicking and popping from the outputs.
With MADI receiver set to 'Activate', I get much, much less regular clicks and pops - however I get drop-outs randomly occurring which can last from one second to 10 seconds, and in most cases there are multiple drop-outs over a short period of time (say, a minute).

Troubleshooting steps:
I've replaced both the BNC cables and the Optical cables.
I've connected the SD11 directly to the Newton, and the signal is clean.
I've setup a number of 18 hour test recordings, recording pink noise through many points of the signal path. XLR out of SD11, Post MADI Router, Post Newton (input), Post Newton (output). In all cases, XLR output is fine. All MADI signals show random clicks much louder than the pink noise, and drop-outs occur a number of hours into the recording.

I'd really like to continue using the MADI stream to output the PA Outputs out of the console, though its proving to be very unreliable with the MADI Router at this stage.

Any help, ideas or thoughts are much appreciated at this stage.

Dylan

  • Max
  • Max
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  • Registered: 2007-05-09
  • Posts: 315

Re: MADI Router - Glitching Issues

Hi Dylan,
how exactly is this done:

The MADI Router then outputs this full stream to an Outline Newton system processor via Optical MADI connections.

do you use the stream routing on the main screen, or is there any matrix involved?

I'm asking because

All devices are clocking off Word Clock, generated by the Outline Newton.

the stream routing is not affected by external word clock. The word clock only affects the four matrices.

However, the matrices do not work if you bypass the MADI receiver.
The entire thing sounds to me like a clocking issue which is caused by the fact that the word clock output of the Newton might not be 100% aligned with the frame start of the outgoing SD-11 signal. Each MADI device is allowed to introduce a certain offset, which usually has no effect, but if as in your case the clock starts from the audio receiver, the offset might become too large and cause these types of issues.

So to align a signal with a clock, I'd try
1. create a matrix that receives all incoming channels from the SD-11
2. route the matrix to the optical output that goes to the Newton
3. activate MADI receivers!
4. clock the matrix to WC in
5. pass MADI subframes.

If that does not work, I'd change 4) and 5):
clock matrix: auto, pass madi subframes
clock matrix: wc, create new madi subframes
clock matrix: auto, create new madi subframes

But back to the initial question - if you used stream routing and bypass MADI receiver, and an optical connection to the Newton, then this has to work. If that was the case, please try other ports at the MADI router (A coax to A optical and C coax to C optical).

Hope this helps.
Best regards,
Max

  • Registered: 2020-01-31
  • Posts: 2

Re: MADI Router - Glitching Issues

Hi Max,

Thanks so much for the prompt reply and suggestions.

To answer your question:
Prior to yesterday I was routing to the Newton using a Matrix, Consisting of SD11 channels as the first channels of the Matrix. Matrix clocking to Word Clock.
Yesterday I changed this to stream routing to try and eliminate the matrix as a potential problem.

In either case, Channel Routing was set to create new MADI subframes.

I will investigate your suggestions and reply here.

Many thanks,

Dylan