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Contributor - Level 3

S16 Optical Glitch

Hey there.
So I have a moderately sized system when I'm running at least four iNuke 6000s per side (two for tops, two for subs). I was trying to figure out a way to run the system where I only have to run one cable across the stage to connect the two S16 heads with the amps. And I had an idea: run ADAT out of an S16, across the stage, and into an ADA8000 8-channel mic pre located in the amp rack, using the eight outputs to feed my amps. So I have a 75' tour-grade optical cable that I run around the stage, and an ADA8000 mounted in the rack permanently wired to the amps. Works like a champ.
... BUT...
There's something in the system where a lot of the time if someone plugs something electrical into the system (a guitarist plugs in his amp, a keyboard player plugs in his keyboard, someone plugs in a fan, etc.), it causes a sharp popping in the side of the PA being fed by the ADAT line. So something inside the S16 is popping at or before the conversion to ADAT stage.
This system works so well I want to wire up both sides of the system like this, one optical cable to each rack, but I have to find a solution to this popping glitch. Does anyone know why it would do this? More to the point, does anyone know how to prevent this popping from happening. Just because someone decides to plug in his iPhone shouldn't cause the system to pop. Any thoughts?
TrevorNelson Contributor - Level 3 2016-08-06

2016-08-06

S16 Optical Glitch

Hey there.
So I have a moderately sized system when I'm running at least four iNuke 6000s per side (two for tops, two for subs). I was trying to figure out a way to run the system where I only have to run one cable across the stage to connect the two S16 heads with the amps. And I had an idea: run ADAT out of an S16, across the stage, and into an ADA8000 8-channel mic pre located in the amp rack, using the eight outputs to feed my amps. So I have a 75' tour-grade optical cable that I run around the stage, and an ADA8000 mounted in the rack permanently wired to the amps. Works like a champ.
... BUT...
There's something in the system where a lot of the time if someone plugs something electrical into the system (a guitarist plugs in his amp, a keyboard player plugs in his keyboard, someone plugs in a fan, etc.), it causes a sharp popping in the side of the PA being fed by the ADAT line. So something inside the S16 is popping at or before the conversion to ADAT stage.
This system works so well I want to wire up both sides of the system like this, one optical cable to each rack, but I have to find a solution to this popping glitch. Does anyone know why it would do this? More to the point, does anyone know how to prevent this popping from happening. Just because someone decides to plug in his iPhone shouldn't cause the system to pop. Any thoughts?

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Contributor - Level 2

Re: S16 Optical Glitch

How long is the ADAT cable actually? More than 10m are not recommended.

How did you wire the AES50? do you supply all components from the same wall socket?
Maybe you have glitches on the AES50 which lead to sync losses on ADAT.
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Contributor - Level 3

Re: S16 Optical Glitch

Ok, so my cable is actually about 23m (75 ft). However, the signal is fine. It's not the audio that's glitchy. It's just a pop when people add or subtract equipment to the power distro. Everything audio (FOH included) is on the same 240 circuit.
It's almost like inside the S16, the optical converter isn't grounded, so any 'spike' - no matter how small - gets transmitted. It doesn't happen when wired via XLR, regardless of cable length.
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Contributor - Level 2

Re: S16 Optical Glitch

Trevor Nelson;82138 wrote:
Ok, so my cable is actually about 23m (75 ft).

With 23m you can be happy that it works at all.
Every small environmental influence will disturb this connection.
Try a shorte ADAT cable.
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Contributor - Level 3

Re: S16 Optical Glitch

Or alternatively use a cat5 - ADAT converter. That will let you run as far as an Ethernet cable can normally be used.

http://appsys.ch/en/products/extenders/adx-8#overview
Contributor - Level 3

Re: S16 Optical Glitch

But would that eliminate the ground "popping" issue? Since the cable wouldn't pick up any electrical interference, and I have no signal issues running the 75' cable, it really seems the problem is created inside the S16. Somehow the electrical issue is messing with the AD, or possibly the DA conversion.
Now that I think about it, it could be on the output conversion side of things too. After all, the wordclock control signal is also running thru the optical cable. I suppose there are any number of places this signal conversion could be breaking down. When I get a chance, I will try it with a 6' (2m) optical cable and see if the popping is still there. If it is, I'll need to try another DA system.

Hey Behringer: would you maybe consider creating a 1U AES50 unit with only outputs for mounting in remote amp racks? 8 outs would be wonderful for getting to the amps on the other side of the stage, controlled like the outputs on the S16 (1-8 or 9-16). Tie it into the system via EtherCon cable. That would make life wonderful.
Just a thought.
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Contributor - Level 3

Re: S16 Optical Glitch

Some of us have previously mentioned a P16O which would use Ultranet rather than AES50 but likewise have 8 or 16 A/Ds to provide the sort of outputs that you need.
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Triber

Re: S16 Optical Glitch

Trevor Nelson;82205 wrote:
...
Hey Behringer: would you maybe consider creating a 1U AES50 unit with only outputs for mounting in remote amp racks? 8 outs would be wonderful for getting to the amps on the other side of the stage, controlled like the outputs on the S16 (1-8 or 9-16). Tie it into the system via EtherCon cable. That would make life wonderful.
Just a thought.


Dear Trevor,
We do have 2RU unit, SD8, that does what you need and even offers 8 spare inputs and 2 bus-powered Ultranet outputs for personal monitoring for talents on stage.
Kind regards,
Jan
_____________________________________________ Jan Duwe, Product Portfolio Manager MUSIC TRIBE Brands DE GmbH