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[Jonathan Betts]

At a recent event after initial setup and tuning of PA system we experienced an extremely loud, shotgun type sound from the system. All in inputs and outputs were muted except for music play back channel/iPod and LR mains.

The sound only happened once. When I looked at the systems monitoring info I noticed a brief spike of approximately 30amps draw. Under normal operating conditions the amp in this particular venue rarely draws more than 10amps and averages around 2-4.

Power was taken from a NEMA 14-50R and the amplifier was run off a L6-30 240v from a power distro.

Console was a Midas Pro 1 running shielded cat 5 to Midas DL 153 stage boxes.

Is this enough info to be helpful for a possible diagnosis?

Thanks!

[Dave Garoutte]

I had power to a stagebox go out once, and when it came back on, Boom.
I always run it on a UPS now.

[Jonathan Betts]

Both stage and FOH were on UPS.

[Don T. Williams]

Could someone have dropped or kicked the CAT 5 while moving it, or stepped (or stomped) on it?  I've had fairly loud popping (not the huge bang you described) when someone moved cable covers and exposed the CAT five to dancers - who proceeded to dance on top of it! 

For what its worth, and I don't think this was the problem, Midas recommends unshielded Cat 5 for the Pro Series and shielded for the M32 series if my memory serves me correctly. I'm not sure it really makes a huge difference, but . . .     

[Mark Wilkinson]

Without trying to diagnose what happened, and like Dave said......I know if a DL-155 gets switched off with amps on...
.... boom big time....crazy big.....
Once, with the DL-155 connected to two PLD amps,  one amp was on, and the other was completely switched off.
I forgot an amp was on, switched the DL-155 off, and kaboom....
...but get this, the amp that was off, and still switched off at the rear power switch, was showing turned on, lit up with red mute lights on the front power switch and with its other displays on too.
What an inductive kickback I guess !

[Jonathan Betts]

What I don’t understand is the huge amperage draw at the time of the incident. It makes me wonder if something funky is going on with the venues mains power supply.

[Rob Spence]

My guess is the huge bang you heard used a bunch of power to make said bang.


Sent from my iPad using Tapatalk Pro

[Chris Grimshaw]

Anything connected to the music input?
I have an old iPod classic here that puts out a loud bang under certain conditions.

+1 on Rob's post above. The 30A peak draw was definitely the bang happening.

Chris

[Jonathan Betts]

The iPod was connected to the console with a 1/8” to 3 pin male/mono XLR cable.

[Mike Caldwell]

The iPod was connected to the console with a 1/8” to 3 pin male/mono XLR cable.

Any chance that phantom power was on at the iPod input.

Personally I always use an isolated interface to connect anything like an iPod to an XLR input.

[ProSoundWeb Community]