phantom power 48 volts

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walters

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What can cause noises in a phantom power unit ?


phantom power is really a 48 volt preamp right?

plus it supplies 48 volts DC on the coil in the mic?


Whats the DC offset for a phantom power unit?
 
walters said:
1. What can cause noises in a phantom power unit ?

2. phantom power is really a 48 volt preamp right?

3. plus it supplies 48 volts DC on the coil in the mic?

4. Whats the DC offset for a phantom power unit?
Click to expand...
1. Noises are the mic signal going thru the power unit. It's normal.

2. No, it's really a 48 volt power supply.

3. If your mic has a coil in it, yes, it will supply 48 volts DC to it.

4. Exactly 48 Volts DC offset, +/- 4 Volts.
 
i had a prob with a soundcraft 1600 a while back. i kept getting some ugly buzz while tracking. i narrowed it down to condensers and promptly took in the power supply in for a checkup. turns out there was somthing up with the power supply and a resistor somewhere. 25$ later my condensers sounded clean. was odd.
 
4. Exactly 48 Volts DC offset, +/- 4 Volts.

isn't that alot of DC offset 48 volts that seems like alot to me for
AC signal to be riding on ?
 
walters said:
4. Exactly 48 Volts DC offset, +/- 4 Volts.

isn't that alot of DC offset 48 volts that seems like alot to me for
AC signal to be riding on ?
Click to expand...

There is no DC offset the voltage supplied to Pins 2 & 3 is from the same supply and is at approx +48v Ref Pin 1.

This is why it does no damage to balanced dynamic mics as each end of the voice coil is at the same potential therefore DC current will not flow thru the coil

Tony
 
wilkee said:
There is no DC offset the voltage supplied to Pins 2 & 3 is from the same supply and is at approx +48v Ref Pin 1.

This is why it does no damage to balanced dynamic mics as each end of the voice coil is at the same potential therefore DC current will not flow thru the coil

Tony
Click to expand...

I've heard that if a dynamic is miswired and voltage does reach the coil, that a worst case scenario would be a melted voice coil and an effectively useless mic. (That pin 1 thing.)

Also, I'm not quite sure, but I think Walters is talking about waveform DC offset as experienced by cheap soundcards, which naturally has absolutely nothing to do with mics, and/or phantom power. The correct answer in this case would indeed be, "The Phantom". YMMV.

Walters my friend, are you or are you not indeed the fantastic new superhero of the current economic slump? If so, whatever happened to Studebaker Hoch, and/or are you him?


Impressed,

sl
 
If proper phantom power damages a nic, please don't blame the poor phantom power supply. Blame either the user or the cable:D
 
Also most phantom power supplies are only capable of supplying 150-200ma max hardly enough to go welding with. Might just about give yer testie's a good tingle.

Tony
 
wilkee said:
Also most phantom power supplies are only capable of supplying 150-200ma max hardly enough to go welding with. Might just about give yer testie's a good tingle.
Click to expand...
Skippy could probably use a good tingle..... :eek:
 
c'mon walters, can you at-least stick to poluteing only the recording forum?
please?
 
walters said:
What can cause noises in a phantom power unit ?


phantom power is really a 48 volt preamp right?

plus it supplies 48 volts DC on the coil in the mic?


Whats the DC offset for a phantom power unit?
Click to expand...

Hi! Micsales here!

Mr. Walters (I can call you Mr., right?)

You are a breath of fresh air in a steaming festering pool of the unknowledgable. Your question is a good one and one worthy of my valuable time and expertise.

Now, +48 volts is term bandied about here on this BBS and one that I feel is the most misunderstood thing out there. Mics do not "use" +48 volts for anything at all. There is an offset, but that offset is there so that the spec sheets can have data in that field. No manufacturer wants his/her mics to look bad. They want all the same functions and "specs" as their competition. Phantom power is one such spec. The "phantom power' name is a bad one because the +48v is *not seen by the mic*!

Think about this walters! A dynamic mic -does not see- this power at all!


So, this "+48v" power is obviously not used for anything at all. It is merely there for show and so that the mic builders can fill out there "spec sheets"

Believe it, but the +48v phantom power comes from the -mixing board- and -not- the mic!

Absurd, no?

Now, the offset question seems a little silly. right?

Hope you keep at the good questions as they all need to be answered by qualified, professional experienced people.
 
wilkee said:
Also most phantom power supplies are only capable of supplying 150-200ma max hardly enough to go welding with. Might just about give yer testie's a good tingle.

Tony
Click to expand...

How much current do you need to weld something that's 0.0001" thick?


sl
 
Phantom power will supply a maximum of 48V/6800 Ohms = 7ma for each leg, a total of 14ma to the device, as the specification calls for a 6.8k resistor in series with the voltage output to each pin (2 and 3).
 
Believe it, but the +48v phantom power comes from the -mixing board- and -not- the mic!


Yea i know but you have to supply 48volts to the mic to give it power

What does phantom power do to the mic?

What is phantom power really?
 
walters said:
Yea i know but you have to supply 48volts to the mic to give it power

What does phantom power do to the mic?

What is phantom power really?
Click to expand...
Each of those questions has already been answered right in this thread.... READ THE FUCKING ANSWERS, SKIPPY................... :rolleyes:
 
walters said:
Believe it, but the +48v phantom power comes from the -mixing board- and -not- the mic!


Yea i know but you have to supply 48volts to the mic to give it power

What does phantom power do to the mic?

What is phantom power really?
Click to expand...


Hi! Micsales here!

I see you have a continuing dilemma that maybe I can answer since Mr. Blue Bear (I can call you Mr., right?) will not or -cannot- provide you with a logical well thought out conclusion.

Anyway, read and learn:

Main Entry: 1phan·tom
Pronunciation: 'fan-t&m
Function: noun
Etymology: Middle English fantosme, fantome, from Middle French fantosme, modification of Latin phantasma
1 a : something (as a specter) apparent to sense but with no substantial existence : APPARITION b : something elusive or visionary : WILL-O'-the-wisp c : an object of continual dread or abhorrence : BUGBEAR <the phantom of disease and want>
2 : something existing in appearance only
3 : a representation of something abstract, ideal, or incorporeal <she was a phantom of delight -- William Wordsworth>
- phan·tom·like /-"lIk/ adverb or adjective


This means that "phantom power" does not exist. It is only there to make recording engineers and soundmen/women seem more important that they really are. If the laymen/women understood this then the engineers would no be able to soak the poor artist of his/her hard earned money.

After all, who wants to screw around with a mic cable/mic if they think that they will be potentially shocked and killed with +48v phantom power?

Do you?

It is good that you are intelligent enough to ask the hard questions as I have taken an oath to tell the home recording community the truth as I see it.
 
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