Phantom power destroying outputs?

Re: Phantom power destroying outputs?

andrew gissing said:
Hi,



Can this cause component damage to the output stage ?



Andrew
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This is what the phantom power from a video camera can do to the aux outputs of a Crest GTX. This despite asking the op 10 times if the phantom power was off. Luckily it didn't do any further damage, and the show went off without a hitch. Camera op paid us the $300 or so that it cost to get it fixed.
 

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Re: Phantom power destroying outputs?

Jason Dermer said:
This is what the phantom power from a video camera can do to the aux outputs of a Crest GTX. This despite asking the op 10 times if the phantom power was off. Luckily it didn't do any further damage, and the show went off without a hitch. Camera op paid us the $300 or so that it cost to get it fixed.
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Same thing happened to me at a charity event at some winery a decade ago. The Vidiot plugged into an "open" Aux out and THEN asked me to dial him up "a nice mono mix".

I did and when he said he wasn't getting any signal, I poked my head in the doghouse, smelled the "magic smoke", unplugged his cable and "very diplomatically" ;-) told him where he could put the connector. His boss was also reminded that requests for a video feed should come something a bit more than five minutes before the program started.

Then MY boss handed him an invoice for the estimated damages.

PS: ALL other outputs of the console continued to work flawlessly.
 
Re: Phantom power destroying outputs?

O1V96: Output makes disconcerting noises when presented with phantom power.

Venice: Channel direct out died after 10 minutes of exposure to phantom power.

Shure UHFR receiver: Various spits, sputters, and crackles that went away when phantom power was turned off.
 
Re: Phantom power destroying outputs?

Jason Dermer said:
This is what the phantom power from a video camera can do to the aux outputs of a Crest GTX. This despite asking the op 10 times if the phantom power was off. Luckily it didn't do any further damage, and the show went off without a hitch. Camera op paid us the $300 or so that it cost to get it fixed.
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This is one reason why my video feeds are isolated with transformers. Always.
 
Re: Phantom power destroying outputs?

Christian Tepfer said:
This is one reason why my video feeds are isolated with transformers. Always.
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One thing that us sound folks might not think about very often is that a transformer-isolated feed also insures US from the associated trouble if WE were to contaminate THEIR signal. The transformer just makes that one less thing to think about.
 
Re: Phantom power destroying outputs?

Christian Tepfer said:
This is one reason why my video feeds are isolated with transformers. Always.
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Mine are, when I "see them coming". In the case I cited above the video guy just plugged in to an XLR output on the console and then TOLD me which one and "requested" what he described as a "nice mono mix"...five minutes before the first speaker approached the podium.

After all he was the VIDEO guy and what he does is SO much more important than what I do
 
Re: Phantom power destroying outputs?

Lee Brenkman said:
Mine are, when I "see them coming". In the case I cited above the video guy just plugged in to an XLR output on the console and then TOLD me which one and "requested" what he described as a "nice mono mix"...five minutes before the first speaker approached the podium.

After all he was the VIDEO guy and what he does is SO much more important than what I do
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That's when I'm definitely not a nice guy. If he somehow qualifies to get a feed I've always got a stereo ISO box handy. If there's no time (takes a couple minutes at most) it's his problem, not mine.
 
As much as I hate to admit it, I think I did the same thing to my motu traveler bringing the reference from one of the outputs back into the mic channel. All of a sudden I was getting these noise spikes like a cap was loading and then discharging. I could not account for it at first but after seeing this thread went back and checked and sure enough, the phantom on channel 2 had gotten turned on probably by pressing the wrong button on the front.

I think I need to set up to use a different input which would mean giving up the ease of adjusting the input gain with the knob on the front.
 
Re: Phantom power destroying outputs?

I always try and use at least a jack to xlr adaptor with no screen connected if "Pro" video geeks are around, a spirit 328 and a soundcraft 200 are 2 devices that I have had damaged by phantom power in the wrong place as well as a having couple of expensive DJ boards make weirder than usual noises or no sound at all G.
 
Re: Phantom power destroying outputs?

There's something like 72 outputs in the main section of a Soundcraft Series 5- I replaced 2 decoupling caps on every one of those outputs because they were always getting hit by phantom power. I went with a 63 volt cap, the stock cap was rated somewhere around 25 volts.
 
Re: Phanton power destroying outputs ?

We had a Soundcraft Spirit at a show, and we were feeding a local radio station a matrix feed into their Mackie. At some point they decided to add SM-81s for crowd mics...turned on their global phantom power and....poof ...suddenly one of the Matrix outputs didn't work. Needless to say they smoked the matrix output by sending it phantom power.
 
Re: Phanton power destroying outputs ?

Tim Woodworth said:
We had a Soundcraft Spirit at a show, and we were feeding a local radio station a matrix feed into their Mackie. At some point they decided to add SM-81s for crowd mics...turned on their global phantom power and....poof ...suddenly one of the Matrix outputs didn't work. Needless to say they smoked the matrix output by sending it phantom power.
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Never, NEVER connect two systems without transformer isolation. Getting unwanted phantom power back is just one of the things you don't want.......
 
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