Phantom Power...

[PropellerHeadCase]

Hi all, just encountered this handy tid-bit (not directly or personally, thankfully) and thought I'd share...

If you're playing at a large function where you're sending your XLR/Canon outs to a side-of-stage or main mixing desk make sure that you are on channels that either have phantom power turned off or, and this may be easier to monitor, make sure you use a de-coupling DI Box to plug into between your leads and theirs (this will save you fried circuitry).

Phantom power is a 48 volt signal that comes back down your wire and there is nothing, electrically, to stop it (and 48V is considerably higher than the standard 1V line signal going the other way).

[NKR]

Just don't plug into a mic or line channel that has a phantom feed.

Why would anyone have phantom on anyway unless they are using a condensor mic and that is unusal in a live situation, they are generally reserved for studio functions.

You got phantom on your desk - most decent desks will have - tape a smarty lid over the button so you don't get accidental phantom.

[Jiggles]

Live situation? Certain DI boxes run off the Phantom power. Bands and the over heads on drums are normally condensers.

[CRAZY K]

Hi all, just encountered this handy tid-bit (not directly or personally, thankfully) and thought I'd share...

If you're playing at a large function where you're sending your XLR/Canon outs to a side-of-stage or main mixing desk make sure that you are on channels that either have phantom power turned off or, and this may be easier to monitor, make sure you use a de-coupling DI Box to plug into between your leads and theirs (this will save you fried circuitry).

Phantom power is a 48 volt signal that comes back down your wire and there is nothing, electrically, to stop it (and 48V is considerably higher than the standard 1V line signal going the other way).

I have phantom power controls on my mixer and my powered mixer but never used it and never ever thought of using it as I dont know what its there for--ignorance is bliss--although yes you can accidentally nudge the button:eek:

Is there more?

Erm do I detect a bit of equipment frying tonight Alan.:confused:

[NKR]

Live situation? Certain DI boxes run off the Phantom power. Bands and the over heads on drums are normally condensers.

I don't run bands, just vocal artists, so only using dymnamic mics in a live situation and a standard dynamic on a xlr should not be affected by phantum anyway. Would never try firing it back into the radio mics though as could well fry the receiver unless someone bright at Senny had foreseen such an incident.

Can't imagine front of house band mics being condenser usually SM58s or Senny's and they are certainly dynamic. Condensers are too delicate for that kind of battering.

[Jiggles]

I don't run bands, just vocal artists, so only using dymnamic mics in a live situation and a standard dynamic on a xlr should not be affected by phantum anyway. Would never try firing it back into the radio mics though as could well fry the receiver unless someone bright at Senny had foreseen such an incident.

Can't imagine front of house band mics being condenser usually SM58s or Senny's and they are certainly dynamic. Condensers are too delicate for that kind of battering.

I know for a fact that the over heads on drums are condensers (normally). Everything else is just dynamics.

[NKR]

I know for a fact that the over heads on drums are condensers (normally). Everything else is just dynamics.

Yeah will give you that one just checked it out. Still you would not find me running a DJ desk into a mic line input as they are the ones with the phantom feeds.

There should be seperate inputs for external desks as I regularly plug my Denon X900 into the Yamaha desk when I have DJ / vocal jobs.

[PropellerHeadCase]

Erm do I detect a bit of equipment frying tonight Alan.:confused:

No sir.


The reason I mentioned this, folks, was purely if you're sending a a feed to a desk with an Op. of unknown skill level and/or unknown familiarity with the desk they're using.

[woody2]

never heard of any problems with phantom power,sounds like a cable wired wrong of faulty equipment,all our DIs and akg mics need it so its always on but i would never plug in or remove cables with the desk on

[TONYTIGER]

I know for a fact that the over heads on drums are condensers (normally). Everything else is just dynamics.

I may be wrong but all our drum mic sets which consist of seven mics all the condensers are self powered with battery inserts so no need for phantom power,i stand to be corrected.

[Jiggles]

I may be wrong but all our drum mic sets which consist of seven mics all the condensers are self powered with battery inserts so no need for phantom power,i stand to be corrected.

Well of course, depends on the mics and such. I know that some can be powered by ether of them depending on the application.

[cjd]

Phantom should be turned off before mics are plugged in so it should be off while all connections are being made - a mistake will never be made this way :)

[csg]

Condensor mics are indeed used in a variety of live situations, i know this doing it day in day out - overheads, hi hat's and acoustic guitars for a start, even string sections etc depending on the job in hand

Some permanently polarised condensors are designed for battery use or remote powering from phantom, phantom is normally used for powering as it tends to be more reliable and lowers the noise floor ( hiss) due the the larger polarising voltage.

phantom power is also usually used for powering active DI boxes, again from the reliability point of view.

In terms of phantom power damaging equipment up line, well that depends on the circuit

If your mixer outputs are balanced XLR's, then the balancing circuit will cancel out any incoming potential from phantom power, so providing that your connection is balanced, then no problem. Just in the same way that plugging a balanced dynamic mic into a circuit with phantom power does it no harm

If your mixer has single ended outputs ( phono), then there is the potential to cause harm. This would normally be negated by the PA crew using DI boxes to turn your unbalanced signal into a balanced one, which is far better at rejecting noise over a cable run.

So, in short, you are worrying needlessly - the only potential for damage would be from plugging your unbalanced output mixer directly into a mic input on a sound desk via a phono - male xlr connector, where the centre phono pin is connected to pin 2. In reality, any pro PA company would avoid this, and either plug you in to line inputs, or as described above, via DI boxes

[TONYTIGER]

Excellent answer,thanks

[DazzyD]

I have phantom power controls on my mixer and my powered mixer but never used it and never ever thought of using it as I dont know what its there for--ignorance is bliss--although yes you can accidentally nudge the button:eek:

Is there more?

Erm do I detect a bit of equipment frying tonight Alan.:confused:

Because of the problems phantom power can cause to equipment, the on/off buttons are usually recessed to avoid being accidentally pressed.

Like you, I've never had the need for phantom power, anyway, so have never used it. But I do know a little about it and what it's for.

[yourdj]

Don't know about that but I unplugged my LD Dave system yesterday for two seconds and it kept playing :eek:

I realized and it kept going as nothing happened!

It was the end of the night by the way :o