phantom power not making it thru wallplates

  • Thread starter Thread starter notbradsohner
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notbradsohner

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So I finally got around to soldering my wall plates. I just finished channel 1, plugged in a sm-57 to the iso room side , and connected the other end of the wall plate to my mixer. Works fine. Then, I go to attach my mxl v67. Nothing. I know the mic works, becuase it will work when I connect it directly to my mixers preamps. Any ideas why my wire isnt carrying phantom power?
 
notbradsohner said:
So I finally got around to soldering my wall plates. I just finished channel 1, plugged in a sm-57 to the iso room side , and connected the other end of the wall plate to my mixer. Works fine. Then, I go to attach my mxl v67. Nothing. I know the mic works, becuase it will work when I connect it directly to my mixers preamps. Any ideas why my wire isnt carrying phantom power?
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size and length of wire? voltage drop over a long length of too small a conductor could = unacceptable voltage.

Or they are wired wrong.
 
I've run phantom power through a 100' snake with no problem. Do you have a multimeter to test with?
 
no multe meter. The cable is only like 4 feet long, and is quad cable. I am almost sure everything is wired up right, how else would all my dynamic mics work?
 
Is it possible you got your + and - wires backwards? In that case the audio signal would just be 180 degrees out of phase but your DC voltage (phantom power) would be backwards and your condesor mics wouldn't be getting the power they need. Dynamic mics would still work.

I'm not a mic expert but that would be my guess.
 
acegunn said:
Is it possible you got your + and - wires backwards? In that case the audio signal would just be 180 degrees out of phase but your DC voltage (phantom power) would be backwards and your condesor mics wouldn't be getting the power they need. Dynamic mics would still work.

I'm not a mic expert but that would be my guess.
Click to expand...

Phantom power is +48V on both pins, so that shouldn't matter. If you grounded pin 2 or 3, I believe a dynamic would still work, albeit unbalanced, but you'd be out the phantom.

It's worth checking your connections again.
 
Before you give yourself a troubleshooting headache, unplug the mic from the far away patch panel, and plug it directly into the console, into the same jack that the patch bay was attached to, and make sure the mic works as well as that input channel.

While unlikely that the mic or the input channel went pfffffft-pop, it's a simple test you can do just to be sure. Then dissect your wiring if the mic works fine directly on the input channel.

and MsHilarious is correct, +48V should be on both the + and - phases of the microphone cable.

If its out of phase, the microphone should still operate, if the ground is wired on the console side. This is how the phantom voltage goes back.

n110fig1b.gif


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n110fig4b.gif
 
When I wired up my wall plates, I tested them before installing them into the walls.
As I was doing new construction, this was simple to do.

I'm guessing you have something wired up wrong.
If you're doing a lot of connections, its easy to get things mixed up.
 
all my wiring is correct, and I actually had that chart when i wired it all up :eek: :eek:

any other ideas?
 
Did you try plugging the mic directly into the same input channel on your mixer?

If that doesn't work, you know something is dead either in the mic, or the console.

If it works, it IS your wiring.
 
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