Phantom power fried my FC12 - will this prevent a third ocurrence?

Patzag

Patzag

Fractal Fanatic
So ... second time for me frying my FC by accidentally plugging in an XLR with phantom power. Will this gizmo protect my FC12 and even allow FASLink2 signal and power to come through? Is there an easy mod to the board that can be made that will protect my FC from the careless and irresponsible behavior I demonstrate every so often?

If I had a single wish, it would be for the power scheme of the FC FASlink to conform to phantom power standard so that this stupid, too-often-made mistake would not result in a very costly repair.

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Ouch. Only someone from Fractal Audio would know if that would still allow power and communication through. But in the meantime, get an XLR cable that is somehow very plainly colored or otherwise marked to avoid ever doing that again.
 
I don’t think this will work for you, but a modified version of it might.

This device blocks DC voltage on two of the three conductors. But FASLink requires voltage on one conductor and a ground on the other. You might be able to apply this to just the signal pin of the FASLink connector, but I’m not sure what that circuit would do to the signal or how long the cable would be before you got too much signal degradation.

I agree that it would be cool if FASLink weren’t susceptible to phantom power.
 
Moke said:
But in the meantime, get an XLR cable that is somehow very plainly colored or otherwise marked to avoid ever doing that again.
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Yes. I had that. But fate and circumstance altered that arrangement and I was trapped by my own lackadaisical attitude in the matter.
 
Patzag said:
Yes. I had that. But fate and circumstance altered that arrangement and I was trapped by my own lackadaisical attitude in the matter.
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After a second misadventure, I'd bet that "lackadaisical attitude" may be gone now, or at least accompanied by a bit more care.

Definitely a drag.
 
@FractalAudio
I have come up with a rather simple way to prevent this from ever happening again, I have XLR barrel turnarounds and will reverse the cable so the "loose end" is male rather than female and my signal cable cannot easily ever be mistaken for an audio cable.
I do however have a question, will the FC accept power and signal through the loop output? If yes, I could just use a turnaround at the Axe FX end only.
I could test it - but I don't really want to chance blowing the thing up a third time.
 
may I ask why not? id like to understand your reasoning. afaik the 1/4" inputs on a board arent phantom powered.
 
PSea said:
may I ask why not? id like to understand your reasoning. afaik the 1/4" inputs on a board arent phantom powered.
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Depending on the venue, you may not have that option. Also, that XLR cable lying on the stage gives you no indication that there is (or is not) a 1/4” connector on the other end.
 
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The DC blocker might work if you power the FC with a separate AC adapter. FASLink uses one of the XLR pins for 12V DC to power the FC unit. If you block that DC power you'll need to provide power using the DC jack on the FC unit instead.

In contrast, standard mic phantom power is 48V DC on both conductors of the XLR cable.
 
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Maybe a bit of a hassle. But if I was gigging I would carry a meter with me. Easy to meter out the females. For the male it’s easy to short things out with test probes. So I’d buy a female jack and measure at the solder lugs or screws. You could elaborate on this by building a small box with jacks hooked up to leds and a dropping resistor.
 
skolacki said:
Maybe a bit of a hassle. But if I was gigging I would carry a meter with me. Easy to meter out the females. For the male it’s easy to short things out with test probes. So I’d buy a female jack and measure at the solder lugs or screws. You could elaborate on this by building a small box with jacks hooked up to leds and a dropping resistor.
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That will tell you whether there’s phantom power on the cable, but it won’t tell you what the cable is connected to. If it’s connected to the mixer, your FC could still be fried if someone hits the phantom power switch. You still need to make sure the other end of the cable is attached to a FASLink port.
 
PSea said:
may I ask why not? id like to understand your reasoning. afaik the 1/4" inputs on a board arent phantom powered.
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Rex said:
Depending on the venue, you may not have that option. Also, that XLR cable lying on the stage gives you no indication that there is (or is not) a 1/4” connector on the other end.
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Exactly that ...
 
WOW, did not know this! Going to switch my XLR for the FC12 to a colored one (90% of my XLR's are black)!! Sorry to hear about your problem, but glad you posted it to make others aware!!! This should DEFINITELY be a BOLD FACED RED NOTE in the FC manual, which I searched just now and it makes no mention of that I can find. Soooooo glad I have the cloud lifter in my mic chain (eats the phantom power and does not pass it AFIK) that I sometimes accidentally plug into the FC, otherwise I would probably have already been a victim of this. Thanks for posting!!!
 
Patzag, I'm very sorry to hear of this happening to you. If you do not mind, would you please provide some context how this happened. I just purchased an Axe FX III Turbo, FC-12 footswitch and a 20' FASLINK cable and would like to prevent this from happening to me as well. If I am correctly reading your initial post, it seems you just plugged in an XLR cable into your FC-12 and Axe FX III then phantom power ran from the Axe FX III to the FC-12 frying your FC-12? Also, would this device help to prevent this from happening?

Phantom Blocker by Triton Audio

Thanks for your time.
 
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e-roq said:
Patzag, I'm very sorry to hear of this happening to you. If you do not mind, would you please provide some context how this happened. I just purchased an Axe FX III Turbo, FC-12 footswitch and a 20' FASLINK cable and would like to prevent this from happening to me as well. If I am correctly reading your initial post, it seems you just plugged in an XLR cable into your FC-12 and Axe FX III then phantom power ran from the Axe FX III to the FC-12 frying your FC-12? Also, would this device help to prevent this from happening?

Phantom Blocker by Triton Audio

Thanks for you time.
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No. The Axe Fx doesn't send phantom power. That comes from a mixer (or maybe an audio interface) that can send phantom power for microphones that require it.

In this case, he accidentally plugged in an XLR from somewhere other than his Axe Fx, and that one had phantom power.
 
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