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A Way To Diffuse Phantom Power?
Old 29th December 2007
  #1
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A Way To Diffuse Phantom Power?

Ok, I'm micing a drum set a pretty minimalist way. But, the problem is, I have some condensors going, but also a ribbon on the kick (Nady RSM4). My mixer only has 1 phontom power switch for all channels. Is there a way to diffuse the phantom power by converting it to TRS and back or something? I also got a digitech gnx2, I was thinking... because for some reason it has a mic in and out, maybe if I run it through there, the phantom power will die out or not transmit through... maybe?
Old 29th December 2007
  #2
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Get a female XLR to TRS balanced adapter.

Pro Co BPBQXF5 | Sweetwater.com

Plug it into the mic cable from the Nady and then into the line in on your mixer.
Old 29th December 2007
  #3
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You should leave the mixers phantom power off and use something like this to supply phantom power to only the mics that need it.
Old 29th December 2007
  #4
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That's more trouble than it's worth, depending on the number of other mics.
Old 29th December 2007
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so xlr to trs will get rid of phantom power?
Old 29th December 2007
  #6
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i spoke to mick hinton of dav electronics recently about this and he said there's an easy and simple mod to a standard XLR cable that can be done to reject phantom power. If you call him he'll either make you one up or tell you the mod.
Old 29th December 2007
  #7
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The phantom power wont hurt the ribbon as long as your cables are wired correctly.
Old 29th December 2007
  #8
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wired correctly as in?

Just xlr straight to the mic?
Old 29th December 2007
  #9
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Quote:
Originally Posted by rackdude View Post
wired correctly as in?

Just xlr straight to the mic?
Correctly as in not miswired. Pin 2 hot, pin 3 common and pin 1 ground for a XLR connection. Phantom will not hurt a ribbon mic unless the cable is not wired correctly.

If pin 1 (ground) is accidentally miswired or shorted to Pin 2 or Pin 3, phantom power can reach the ribbon element and damage it.

Here's the other exception- pasted from Royer Labs website because I'm too lazy to type it all out.... I dont think it's applicable to your situation because you dont seem to be using a patch bay, but I thought I'd include it anyway just to be thorough...

{{{ Cross-Patching Microphone Tie Lines-

This is the leading cause of blown ribbons in professional studios!

Many studios use patch bays for the convenient routing of signals. The microphone/mic-preamplifier section of a patch bay normally has two rows. The upper row corresponds to lines that run to various microphone panels (studio, isolation booth, etc.) and this is where the microphone is connected. The lower row represents the microphone preamplifier inputs. This upper row is "normaled" to the lower row. Each insert is a full-break patch point, which enables an engineer to crosspatch or redirect microphone lines to various mic-preamp inputs.

The microphone/mic-preamplifier section is the only portion of a patch bay that has DC power present in the form of phantom power. If phantom power is on, ribbon microphones can be damaged when cross-patched through a patch bay.

Here’s what happens. Patch cables utilize "tip-ring-sleeve" connectors. When a patch cable is inserted into either the upper or lower row, the phantom power is momentarily shorted to connections that phantom power should not be applied to. In other words, as the connector is inserted, it is, in effect, acting (temporarily) like a miss-wired cable and applying phantom power to the wrong leads. Ribbon mics are particularly intolerant to this because, in the brief moment that a patch cable is being inserted into a phantom-power-charged patch bay, phantom power is applied directly to the ribbon element through the transformer! Each brief patching-related jolt of phantom power across the ribbon element is equivalent to a year or more of recordings made on the mic. A ribbon element that is designed to last ten or fifteen years before replacement can literally be blown overnight by patch bay mishaps.

The only safe way to reroute mic tie-lines that are present at the patch bay is to be certain that phantom power is deactivated before patching. Cross-patching these lines while "hot" often results in damage to ribbons and even some condenser microphones. Since DC voltages are present on these lines, cross patching with the volume control up can also result in damaged monitor speakers and shaken eardrums!
}}}

Its pretty shocking to me to see all the mis-informed posts above. Don't post if you dont know what the hell you're talking about!
Old 29th December 2007
  #10
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well, i got it now. Thanks. I took the suggestion of a xlr to trs and tried it on a condenser using the line in on the mic preamp, didn't get a signal because the phantom doesn't transmit through the line...

so, I can ribbon in like that. But, then its line using the line in gain...

is that worse?
Old 29th December 2007
  #11
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Who's misinformed? He doesn't have a patchbay and a XLR->TRS cable is just what he needed...

Also, the same thing with the patchbay is why you shouldn't use ribbons with phantom power I thought: even if your cable is fine if you accidentally hot plug it it'll blow the ribbon.
Old 29th December 2007
  #12
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Quote:
Originally Posted by Corran View Post
Who's misinformed? He doesn't have a patchbay and a XLR->TRS cable is just what he needed...
Also, the same thing with the patchbay is why you shouldn't use ribbons with phantom power I thought: even if your cable is fine if you accidentally hot plug it it'll blow the ribbon.
You and the other two is who. (I'm a regular Dr Seuss)

You really think that plugging a ribbon mic into a line input is the way to go?
I guess I dont enjoy the sound of hiss as much as you. Most ribbons need more gain then a line input can deliver anyway.

He didn't need anything. And the people who read this post dont need misinformation. He just needs to plug the mic in and record after maybe double checking that his xlr cables are up to snuff. (meaning not miswired and not shorting out)
Old 29th December 2007
  #13
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I don't know too much about XLR cables other than they connect things and I'm not using a patchbay so I'm just gonna use the line in. I don't need too much gain because I only need this setup for a kick and a loud cab.

Unless you mean my XLR cable is up to snuff as in I own a magonomi? I didn't modify anything, would that mean its safe? Or does it need to be modified?
Old 29th December 2007
  #14
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Whatever. The info is there. If you want to listen to people who tell you to use a line level input for a ribbon mic, be my guest.
Old 29th December 2007
  #15
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Well he isn't going to be happy if he blows his ribbon by accidentally hot-plugging it. Anyway, he asked how to diffuse phantom power, I answered the question. He didn't ask if a ribbon would be okay with phantom power on.
Old 29th December 2007
  #16
jhg
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Why even use a ribbon mic if you're not going to give it the gain it requires?

Test your cable: make sure pin 1 is going to 1, 2 - 2, 3 - 3. and nowhere else. Then plug in and don't worry.
Old 29th December 2007
  #17
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Well exactly, neither the xlr or trs input will have all the clean gain he needs most likely.
Old 29th December 2007
  #18
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Sigma's Avatar
this has been brought up numerous times...older consoles like the mci were wired phantom on ALL THE TIME..as long as you are wired correctly don't worry
Old 29th December 2007
  #19
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Alright so did I hear this wrong before?

If you plug in a ribbon mic with the phantom power on, will it or will it not blow the ribbon??

I know the phantom will probably not blow the ribbon itself, I just understood that it will if you hot plug it. And I'm not going to try this with my B&O I just got!
Old 29th December 2007
  #20
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Quote:
Originally Posted by Corran View Post
Well exactly, neither the xlr or trs input will have all the clean gain he needs most likely.
You dont know what you're talking about.

There's a quote by Lincoln that comes to mind....
"Better to remain silent and be thought a fool then to speak out and remove all doubt."
Old 29th December 2007
  #21
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Okay, you've been nothing but rude and not addressing WHY I'm wrong. People use preamps on ribbons for a reason, because the ribbon doesn't have much output. So his board probably will push the ribbon at extreme gain with whatever noise comes with that.

Again, I addressed his problem, rather than tell him to go spend $$$ to get a preamp and not enable phantom power.

I was just trying to help. You are just being an ass. I will go ahead and say I'm sure that you have a ton more experience and expertise, but you don't have to be a jerk. I have my own recording business (location recording of classical/jazz) and I've gotten great results from ribbons when I had to use the line-in on my digital mixer, though I usually use a preamp.

So again, correct me if I'm wrong, he WILL blow the ribbon if he hot plugs a phantom powered cable into the ribbon, correct?
Old 29th December 2007
  #22
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the ribbon mike doesn't see the phantom if everything is pinned properly
Old 29th December 2007
  #23
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Quote:
Originally Posted by Sigma View Post
the ribbon mike doesn't see the phantom if everything is pinned properly
I understand that, but what about hot-plugging??
Old 29th December 2007
  #24
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Quote:
Originally Posted by Corran View Post
I understand that, but what about hot-plugging??
what is the hot plugging you speak of..if it's plugging the mic in with phantom on it's not an issue
Old 29th December 2007
  #25
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Yeah that's what I meant.

So the whole time the "phantom power will hurt ribbons" thing was an urban myth or something? I mean, doesn't Nady et al still send disclaimers to not use phantom power?

Also I thought I remember hearing that vintage ribbons have more of a tendency to be harmed by phantom power. Which is what I'm concerned about with my vintage B&O.
Old 29th December 2007
  #26
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Quote:
Originally Posted by Corran View Post
Okay, you've been nothing but rude and not addressing WHY I'm wrong. People use preamps on ribbons for a reason, because the ribbon doesn't have much output. So his board probably will push the ribbon at extreme gain with whatever noise comes with that.

Again, I addressed his problem, rather than tell him to go spend $$$ to get a preamp and not enable phantom power.

I was just trying to help. You are just being an ass. I will go ahead and say I'm sure that you have a ton more experience and expertise, but you don't have to be a jerk. I have my own recording business (location recording of classical/jazz) and I've gotten great results from ribbons when I had to use the line-in on my digital mixer, though I usually use a preamp.

So again, correct me if I'm wrong, he WILL blow the ribbon if he hot plugs a phantom powered cable into the ribbon, correct?

Having to post over and over again to try and correct the misinformation posted by newbies is frustrating... He doesn't have a patchbay so "hot patching" is not an issue. If he plugs a correctly wired XLR cable into a his ribbon mic with the phantom power on it will not hurt the mic.

A line level input is usually โ€“20dB to +10dB of gain

A mic input is usually around 0dB to +60dB (or more depending on the preamp)

Some digital mixers can access the mic preamp from the TRS input (the 01V96 for example) but that is not the norm and its not really a line level input although it can often be used that way. So you're just confusing this poor guy by telling him to plug a ribbon into his line input. Its wrong and the correct answer to his question is what I posted above.
Old 29th December 2007
  #27
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Quote:
Originally Posted by Corran View Post
Yeah that's what I meant.

So the whole time the "phantom power will hurt ribbons" thing was an urban myth or something? I mean, doesn't Nady et al still send disclaimers to not use phantom power?

Also I thought I remember hearing that vintage ribbons have more of a tendency to be harmed by phantom power. Which is what I'm concerned about with my vintage B&O.
Yes, its a myth in every other instance than what I've posted above. Some older ribbons are wired differently than the standard, which is why you need to be careful to know how they are wired before using them with phantom power.
Old 29th December 2007
  #28
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Alright thank you.

I think my problem is that I have a digital mixer and I've actually never used my ribbons on one of my analog mixers. My fault. Edit: That is to say that I get plenty of gain from the line-ins on the digital mixer.

I also had some knowledgable people tell me to not plug in a ribbon with phantom power on. They need to get their act together. This was a guy who worked on ribbon mics no less!


Quote:
Originally Posted by De chromium cob View Post
Having to post over and over again to try and correct the misinformation posted by newbies is frustrating... He doesn't have a patchbay so "hot patching" is not an issue. If he plugs a correctly wired XLR cable into a his ribbon mic with the phantom power on it will not hurt the mic.

A line level input is usually โ€“20dB to +10dB of gain

A mic input is usually around 0dB to +60dB (or more depending on the preamp)

Some digital mixers can access the mic preamp from the TRS input (the 01V96 for example) but that is not the norm and its not really a line level input although it can often be used that way. So you're just confusing this poor guy by telling him to plug a ribbon into his line input. Its wrong and the correct answer to his question is what I posted above.
Old 29th December 2007
  #29
YZ!
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Unless you know the particular mixer/preamp that's going to be used, advising the use of a simple XLR-to-TRS converter could put the user in the very same danger he was trying to avoid.

Good that the OP tried the converter with a condenser mic and verified that his particular equipment does not feed phantom into the TRS input.

It does not do it because his TRS input is a line input.

You do know that there are combo TRS/XLR jacks, and that some pieces of gear use them on mic inputs, and that some of them do feed phantom to both connections, don't you?

So, the OP asked for a way to avoid getting phantom to his ribbon mic, and your reply could have led him to get phantom to it.
Old 29th December 2007
  #30
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Quote:
so, I can ribbon in like that. But, then its line using the line in gain...

is that worse?
Yes, it is worse...

Quote:
Well exactly, neither the xlr or trs input will have all the clean gain he needs most likely.
We don't know what kind of mixer he has so we can't know for sure whether the XLR input will have enough gain or not...but the preamps built into most mixers will be fine for a ribbon used on a source as loud as a kick drum. The line input most likely will not.

Quote:
Anyway, he asked how to diffuse phantom power, I answered the question. He didn't ask if a ribbon would be okay with phantom power on.
If it wasn't stated outright, it was certainly implied...

Quote:
If you plug in a ribbon mic with the phantom power on, will it or will it not blow the ribbon??
No, it won't...the nice thing about an XLR is all three pins go in at once and there's no chance of pluggint it in the wrong way. With a TRS cable in a patchbay the voltage can get applied to the wrong coductor which is what will blow the ribbon. Which is why they say that as long as the cable is wired correctly you won't blow a ribbon with phantom...if the ground is wired to one of the pins that phantom appears on, though, you will have a problem.

Running mic lines through a patchbay is scary in general, because it's very easy to apply phantom power to all kinds or places where it doesn't belong...

I don't think it's necessarily bad advice to recommend against plugging a ribbon microphone into a phantom-powered input, but with any of the current microphones on the market it really shouldn't be an issue.

Quote:
Unless you know the particular mixer/preamp that's going to be used, advising the use of a simple XLR-to-TRS converter could put the user in the very same danger he was trying to avoid.

Good that the OP tried the converter with a condenser mic and verified that his particular equipment does not feed phantom into the TRS input.

It does not do it because his TRS input is a line input.

You do know that there are combo TRS/XLR jacks, and that some pieces of gear use them on mic inputs, and that some of them do feed phantom to both connections, don't you?
Actually, if a mixer does have TRS inputs where phantom is applied (which is unusual and not the way it should be...I don't know of any mixer that works that way and only one audio interface...in most cases the phantom power does not appear on the TRS connetor) that would be the only way there was really any danger as the XLR connection shouldn't be a problem at all.
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