Adapting a microphone to remote phantom power

[Dave Plowman (News)]

In article <XsmdnYdVkYGx7n_UnZ2dnUVZ_hqdnZ2d@earthlink.com>,
Michael A. Terrell <mike.terrell@earthlink.net> wrote:

Ah. That explains things. Perhaps if you actually used those mics in
anger you'd know what to ask for.

The only electronics I used in anger was in the US military. The
anger was due to the twisted 'catch 22' regulations of zero allowed
downtime, and everything being 'depot level maintenance. If you had the
proper security clearance you would see how I handled the problem, and
the results of my decisions.

I know what to ask for, even when some fool has given it a stupid
name.

Then I'd have expected you to be in favour of accuracy.

Phantom powering for mics is a tightly defined standard.

Line powering can mean anything.

If you want to call line powering phantom carry on. You're then the fool
who has given it a stupid name.

--
* What do they call a coffee break at the Lipton Tea Company? *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[David Nebenzahl]

On 4/12/2009 4:13 PM Dave Plowman (News) spake thus:

Phantom powering for mics is a tightly defined standard.

Line powering can mean anything.

You keep saying this, which doesn't make it any more or less true.

Can you quote a reliable, authoritative source that defines phantom
power so? (And puleeze, don't even *think* about using Wikipedia!) One
which says that phantom power (R)(TM) *must* include the use of balanced
inputs, etc., as you've been claiming?

If there exists such a definition online, that could settle the whole
matter pretty easily.


--
Save the Planet
Kill Yourself

- motto of the Church of Euthanasia (http://www.churchofeuthanasia.org/)

 

[Franc Zabkar]

On Sat, 11 Apr 2009 11:41:30 -0700, David Nebenzahl
<nobody@but.us.chickens> put finger to keyboard and composed:

So let's see what others have to say about "phantom power", shall we? A
good starting point is to let Google sort it out: a simple search with
"definehantom power" yields the following:

o the Wikipedia article, which agrees with you
o http://www.dramatic.com.au/glossary/glossaryp_z.htm, which says
nothing about the balanced requirement (agrees w/me)
o http://www.learnchurchsound.com/definitions/acoustical-terms.php, ditto
o http://www.woken.com.tw/internal/service/glossary.php, agrees w/you
o
http://www.britishtheatreguide.info/otherresources/glossary/glossps.htm,
which agrees w/me (except for the odd assertion that "Phantom power can
only be used when the connectors are XLR" (???)

DISCLAIMER: I make no claim that any of the above "citations" are
authoritative (least of all the Wikipedia entry). My intention is to
show that, contrary to your (and Dave Plowman's) insistent assertions,
there seems to be no general agreement that the term "phantom power" is
as restrictive as you claim it is. (See Arfa Daily's postings on the
subject for corroboration.)

I was curious as to what a microphone manufacturer had to say.

For example, Shure considers that "phantom power" and "bias" are two
different concepts:
http://www.shure.com/ProAudio/Products/us_pro_ea_phantom

Sennheiser also appears to differentiate between phantom power (48V)
and T or A-B power (12V):
http://www.sennheiserusa.com/faq/faq.asp?transid0=0005

And then there's this site:
http://www.epanorama.net/circuits/microphone_powering.html

Phantom power now appears to be defined by a prevailing standard, DIN
EN 61938, July 97, formerly DIN IEC 268-15 and DIN 45 596.

That said, I'd always used the terms "phantom power" and "bias"
interchangeably, but my knowledge of microphones is essentially zero.

There are other systems where power is supplied to the remote device
via the signal cable, eg a masthead amp, or a video camera, or an LNB
for a satellite dish. I think these are generally referred to as being
*line* powered. Instead of a resistor, the series element is an
inductor. This has a low impedance at DC, or AC mains frequency, but a
high impedance at video frequencies.

Then there are those devices which can be considered to be *signal*
powered, eg serial mice which rob power from the DTR and RTS signals
(?) of an RS232 port.

So I guess the moral of the story is that one has to be aware that not
everyone speaks the same language, whether or not they are correct.
However I'd tend to lean towards a definition that is incorporated
into an accepted standard. Unfortunately DIN/EN 61938 does not appear
to be available as a free download. :-(

The funny thing is that telephones can be considered to be phantom
powered, yet I'd never heard the term used in that context until I
read the Wikipedia article on the subject.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Dave Plowman (News)]

In article <49e29c7f$0$2694$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

On 4/12/2009 4:13 PM Dave Plowman (News) spake thus:

Phantom powering for mics is a tightly defined standard.

Line powering can mean anything.

You keep saying this, which doesn't make it any more or less true.

Can you quote a reliable, authoritative source that defines phantom
power so? (And puleeze, don't even *think* about using Wikipedia!) One
which says that phantom power (R)(TM) *must* include the use of balanced
inputs, etc., as you've been claiming?

I get some 197,000 hits when I Google for phantom power. And can't be
bothered wading through all of them.

Lets just say it's an album from Super Furry Animals if Google is your
source of things technical.

If there exists such a definition online, that could settle the whole
matter pretty easily.

I've a feeling if I gave you such a site you'd just rubbish it as you do
Wikipedia if it doesn't agree with you.

--
*Ever stop to think and forget to start again?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[David Nebenzahl]

On 4/13/2009 12:55 AM Dave Plowman (News) spake thus:

In article <49e29c7f$0$2694$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

On 4/12/2009 4:13 PM Dave Plowman (News) spake thus:

Phantom powering for mics is a tightly defined standard.

Line powering can mean anything.

You keep saying this, which doesn't make it any more or less true.

Can you quote a reliable, authoritative source that defines phantom
power so? (And puleeze, don't even *think* about using Wikipedia!) One
which says that phantom power (R)(TM) *must* include the use of balanced
inputs, etc., as you've been claiming?

I get some 197,000 hits when I Google for phantom power. And can't be
bothered wading through all of them.

Lets just say it's an album from Super Furry Animals if Google is your
source of things technical.

If there exists such a definition online, that could settle the whole
matter pretty easily.

I've a feeling if I gave you such a site you'd just rubbish it as you do
Wikipedia if it doesn't agree with you.

In other words, I can't be bothered to come up with a fucking citation
to back myself up.

Why didn't you just say so? Fewer electrons would've been tortured in
the process.


--
Save the Planet
Kill Yourself

- motto of the Church of Euthanasia (http://www.churchofeuthanasia.org/)

 

[Dave Plowman (News)]

In article <8aa5u4dkkdcf9m7tobqdaqgo3h3caa908c@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:

DISCLAIMER: I make no claim that any of the above "citations" are
authoritative (least of all the Wikipedia entry). My intention is to
show that, contrary to your (and Dave Plowman's) insistent assertions,
there seems to be no general agreement that the term "phantom power" is
as restrictive as you claim it is. (See Arfa Daily's postings on the
subject for corroboration.)

I was curious as to what a microphone manufacturer had to say.

For example, Shure considers that "phantom power" and "bias" are two
different concepts:
http://www.shure.com/ProAudio/Products/us_pro_ea_phantom

That explains things pretty well.

Sennheiser also appears to differentiate between phantom power (48V)
and T or A-B power (12V):
http://www.sennheiserusa.com/faq/faq.asp?transid0=0005

As does that - although it only talks about one other version of line
powering, T or AB, which is again a defined standard as it's dealing with
basically pro mics. Many mics (especially on consumer goods) use a
different line power voltage to the 12 volts of T power, as it's only
usually to power an FET etc to do impedance matching.

And then there's this site:
http://www.epanorama.net/circuits/microphone_powering.html

Phantom power now appears to be defined by a prevailing standard, DIN
EN 61938, July 97, formerly DIN IEC 268-15 and DIN 45 596.

That appears pretty definitive.

That said, I'd always used the terms "phantom power" and "bias"
interchangeably, but my knowledge of microphones is essentially zero.

Anywhere that sold phantom powered mics would require you to know what
they were when buying, otherwise you might end up with one which didn't
work to your requirements.

There are other systems where power is supplied to the remote device
via the signal cable, eg a masthead amp, or a video camera, or an LNB
for a satellite dish. I think these are generally referred to as being
*line* powered. Instead of a resistor, the series element is an
inductor. This has a low impedance at DC, or AC mains frequency, but a
high impedance at video frequencies.

Indeed.

Then there are those devices which can be considered to be *signal*
powered, eg serial mice which rob power from the DTR and RTS signals
(?) of an RS232 port.

So I guess the moral of the story is that one has to be aware that not
everyone speaks the same language, whether or not they are correct.
However I'd tend to lean towards a definition that is incorporated
into an accepted standard. Unfortunately DIN/EN 61938 does not appear
to be available as a free download. :-(

The funny thing is that telephones can be considered to be phantom
powered, yet I'd never heard the term used in that context until I
read the Wikipedia article on the subject.

No - telephones are line powered. True phantom power was however first
used in the telephone industry for other purposes.

A telephone line is balanced - but if you apply an AVO to that line you'll
see the DC. Do the same to a balanced mic line with phantom power present
and you won't.

--
*60-year-old, one owner - needs parts, make offer

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Dave Plowman (News)]

In article <49e2f238$0$2699$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

I've a feeling if I gave you such a site you'd just rubbish it as you
do Wikipedia if it doesn't agree with you.

In other words, I can't be bothered to come up with a fucking citation
to back myself up.

The Wikipedia explains phantom powering perfectly satisfactorily.

Why didn't you just say so? Fewer electrons would've been tortured in
the process.

Ok smartarse. But then I wouldn't be posting here for advice on how to
power a mic. Any mic.

--
*Who are these kids and why are they calling me Mom?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Michael A. Terrell]

"Dave Plowman (News)" wrote:

In article <8aa5u4dkkdcf9m7tobqdaqgo3h3caa908c@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:
DISCLAIMER: I make no claim that any of the above "citations" are
authoritative (least of all the Wikipedia entry). My intention is to
show that, contrary to your (and Dave Plowman's) insistent assertions,
there seems to be no general agreement that the term "phantom power" is
as restrictive as you claim it is. (See Arfa Daily's postings on the
subject for corroboration.)

I was curious as to what a microphone manufacturer had to say.

For example, Shure considers that "phantom power" and "bias" are two
different concepts:
http://www.shure.com/ProAudio/Products/us_pro_ea_phantom

That explains things pretty well.

Sennheiser also appears to differentiate between phantom power (48V)
and T or A-B power (12V):
http://www.sennheiserusa.com/faq/faq.asp?transid0=0005

As does that - although it only talks about one other version of line
powering, T or AB, which is again a defined standard as it's dealing with
basically pro mics. Many mics (especially on consumer goods) use a
different line power voltage to the 12 volts of T power, as it's only
usually to power an FET etc to do impedance matching.

And then there's this site:
http://www.epanorama.net/circuits/microphone_powering.html

Phantom power now appears to be defined by a prevailing standard, DIN
EN 61938, July 97, formerly DIN IEC 268-15 and DIN 45 596.

That appears pretty definitive.

That said, I'd always used the terms "phantom power" and "bias"
interchangeably, but my knowledge of microphones is essentially zero.

Anywhere that sold phantom powered mics would require you to know what
they were when buying, otherwise you might end up with one which didn't
work to your requirements.

There are other systems where power is supplied to the remote device
via the signal cable, eg a masthead amp, or a video camera, or an LNB
for a satellite dish. I think these are generally referred to as being
*line* powered. Instead of a resistor, the series element is an
inductor. This has a low impedance at DC, or AC mains frequency, but a
high impedance at video frequencies.

Indeed.

Then there are those devices which can be considered to be *signal*
powered, eg serial mice which rob power from the DTR and RTS signals
(?) of an RS232 port.

So I guess the moral of the story is that one has to be aware that not
everyone speaks the same language, whether or not they are correct.
However I'd tend to lean towards a definition that is incorporated
into an accepted standard. Unfortunately DIN/EN 61938 does not appear
to be available as a free download. :-(

The funny thing is that telephones can be considered to be phantom
powered, yet I'd never heard the term used in that context until I
read the Wikipedia article on the subject.

No - telephones are line powered. True phantom power was however first
used in the telephone industry for other purposes.

A telephone line is balanced - but if you apply an AVO to that line you'll
see the DC. Do the same to a balanced mic line with phantom power present
and you won't.

Then you don't know how to properly connect anything to the phone
line, other than a cheap imported telephone.

Powering a microphone isn't rocket science, no matter how much you
try to build it up. So what if the DC is applied to both sides of a
balanced microphone circuit. that was done to prevent morons from
frying a dynamic microphone by using it with the wrong equipment.
Trying to idiot proof simple technology is no big deal, till they breed
bigger and bigger idiots who have ego problems. A modern design would
use RF on the line to eliminate any possible hum, and be high enough
that it couldn't interact with the audio. That wasn't possible with
early phantom mics, using tube preamps. The same tube preamps that like
to break into oscillation at times, or became microphonic.

--
You can't have a sense of humor, if you have no sense!

 

[Dave Plowman (News)]

In article <sqOdnceeuKNIzH7UnZ2dnUVZ_tCdnZ2d@earthlink.com>,
Michael A. Terrell <mike.terrell@earthlink.net> wrote:

A telephone line is balanced - but if you apply an AVO to that line
you'll see the DC. Do the same to a balanced mic line with phantom
power present and you won't.

Then you don't know how to properly connect anything to the phone
line, other than a cheap imported telephone.

Could you take me through that statement step by step?

Powering a microphone isn't rocket science, no matter how much you
try to build it up. So what if the DC is applied to both sides of a
balanced microphone circuit. that was done to prevent morons from
frying a dynamic microphone by using it with the wrong equipment.

Thanks for confirming you know nothing about the use of microphones. I
suppose you'd have dozens of different connectors on each channel input to
satisfy your 'military spec' attitude? And dozens of different cables to
go with those?

Trying to idiot proof simple technology is no big deal, till they breed
bigger and bigger idiots who have ego problems.

You certainly know about that.

A modern design would use RF on the line to eliminate any possible hum,

You get hum from DC?

and be high enough that it couldn't interact with the audio.

Given any thought to cable design? And the lengths those often are? Over a
mile is common.

That wasn't possible with early phantom mics, using tube preamps.

Dunno where you got the idea of *early* phantom mics being tube. If there
were any they weren't in common use. The first mainstream phantom power
mic was the Neumann KM 84. And it wasn't a tube mic. Previous condenser
valve mics used individual power supplies via multicore cable. With all
the problems that caused in a large rig.

The same tube preamps that like to break into oscillation at times, or
became microphonic.

I suppose you only came across broken ones. In practice, oscillation was
rare. With good makes, of course.

--
*I'm planning to be spontaneous tomorrow *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Michael A. Terrell]

"Dave Plowman (News)" wrote:

In article <sqOdnceeuKNIzH7UnZ2dnUVZ_tCdnZ2d@earthlink.com>,
Michael A. Terrell <mike.terrell@earthlink.net> wrote:
A telephone line is balanced - but if you apply an AVO to that line
you'll see the DC. Do the same to a balanced mic line with phantom
power present and you won't.

Then you don't know how to properly connect anything to the phone
line, other than a cheap imported telephone.

Could you take me through that statement step by step?

Why, you still wouldn't get it.

Powering a microphone isn't rocket science, no matter how much you
try to build it up. So what if the DC is applied to both sides of a
balanced microphone circuit. that was done to prevent morons from
frying a dynamic microphone by using it with the wrong equipment.

Thanks for confirming you know nothing about the use of microphones.

YAwn. Thanks for proving nothing.

I
suppose you'd have dozens of different connectors on each channel input to
satisfy your 'military spec' attitude? And dozens of different cables to
go with those?

Sigh, you are more than brain dead. WTF would the military
intentionally shoot themselves in both feet? What part of
'specification' don't you understand? There were three types of
connectors. XLR, terminal blocks and patch bays. Everything except the
magnetic phono circuits and headphone jacks were balanced. Obviously
you know nothing about the reasons the military uses standards.

Trying to idiot proof simple technology is no big deal, till they breed
bigger and bigger idiots who have ego problems.

You certainly know about that.

Its confirmed with every idiotic post you make.

A modern design would use RF on the line to eliminate any possible hum,

You get hum from DC?

It can be picked up on a DC circuit. Why do you think they use HF AC
to power the lamp used in film projectors, instead of DC? Its easier to
rectify & filter a power source well above the needed audio bandwidth,
than deal with electrical noise is some locations. try your DC power in
places near a substation, where the AC magnetic field can affect video
monitors, or a high power transmitter causes ingression problems. No
circuit is a perfect balance in those situations.

and be high enough that it couldn't interact with the audio.

Given any thought to cable design? And the lengths those often are? Over a
mile is common.

Yawn. At a mile I would look into fiber or an RF link. Try running
a mile of audio cable in a place with a lot of lighting is sheer
stupidity. I had a lightning strike at my last house. It hit the
buried phone cable and vaporized the copper in 1.2 miles of buried,
shielded six pair cable. then it wiped out the subscriber interface
circuit for mine, and 15 other houses and destroyed the copper pair back
to the central office.

I had a T studio building hit by lightning as well. it blew out
chunks of concrete, and wiped out our computer network, 11 GHz STL and
four C-band LNBs, most of the satellite receivers and the 1A2 telephone
system I replaced a lot of damaged wire.

That wasn't possible with early phantom mics, using tube preamps.

Dunno where you got the idea of *early* phantom mics being tube. If there
were any they weren't in common use. The first mainstream phantom power
mic was the Neumann KM 84. And it wasn't a tube mic. Previous condenser
valve mics used individual power supplies via multicore cable. With all
the problems that caused in a large rig.

The same tube preamps that like to break into oscillation at times, or
became microphonic.

I suppose you only came across broken ones. In practice, oscillation was
rare. With good makes, of course.

There are some records that were released with the mics acting up.
Of course, you don't know what I'm talking about.



--
You can't have a sense of humor, if you have no sense!

 

[Franc Zabkar]

On Mon, 13 Apr 2009 09:14:18 +0100, "Dave Plowman (News)"
<dave@davenoise.co.uk> put finger to keyboard and composed:

In article <8aa5u4dkkdcf9m7tobqdaqgo3h3caa908c@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:

That said, I'd always used the terms "phantom power" and "bias"
interchangeably, but my knowledge of microphones is essentially zero.

Anywhere that sold phantom powered mics would require you to know what
they were when buying, otherwise you might end up with one which didn't
work to your requirements.

I confess I'm ignorant about professional audio gear. I've always
thought of phantom power as a generic term, and it appears that many
people do likewise.

In fact the Wikipedia article recognises this:

=====================================================================
The low-current 3 to 5 V supply provided at the microphone jack of
some consumer equipment, such as portable recorders and computer sound
cards, is sometimes called "phantom power."
=====================================================================

I can see a parallel in the definition of USB standards:
http://www.usb.org/developers/packaging/:

=====================================================================
Because the USB 2.0 Specification encompasses all USB data transfer
speeds, low (1.5Mb/s), full (12Mb/s) and high (480Mb/s), it is
important that vendors clearly communicate the type of product on
packaging and in marketing and advertising materials. Inconsistent use
of terminology in combination with the existing general misconception
that USB 2.0 is synonymous with Hi-Speed USB ... creates confusion in
the marketplace.
=====================================================================

One would think that low, full, and high speed are loose, generic
terms, but in the USB context they have particular numbers associated
with them.

The funny thing is that telephones can be considered to be phantom
powered, yet I'd never heard the term used in that context until I
read the Wikipedia article on the subject.

No - telephones are line powered. True phantom power was however first
used in the telephone industry for other purposes.

A telephone line is balanced - but if you apply an AVO to that line you'll
see the DC. Do the same to a balanced mic line with phantom power present
and you won't.

OK, I see now ...
http://www.mediacollege.com/audio/phantom-power/

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Dave Plowman (News)]

In article <J-mdnYIQiM3DHX7UnZ2dnUVZ_vqdnZ2d@earthlink.com>,
Michael A. Terrell <mike.terrell@earthlink.net> wrote:

"Dave Plowman (News)" wrote:

In article <sqOdnceeuKNIzH7UnZ2dnUVZ_tCdnZ2d@earthlink.com>,
Michael A. Terrell <mike.terrell@earthlink.net> wrote:
A telephone line is balanced - but if you apply an AVO to that line
you'll see the DC. Do the same to a balanced mic line with phantom
power present and you won't.

Then you don't know how to properly connect anything to the phone
line, other than a cheap imported telephone.

Could you take me through that statement step by step?

Why, you still wouldn't get it.

That'll be a no, then.

Powering a microphone isn't rocket science, no matter how much you
try to build it up. So what if the DC is applied to both sides of a
balanced microphone circuit. that was done to prevent morons from
frying a dynamic microphone by using it with the wrong equipment.

Thanks for confirming you know nothing about the use of microphones.

YAwn. Thanks for proving nothing.

If you even gave it a modicum of thought you'd realise the ability to have
one connector and type of cable for virtually any microphone has real
benefits. But then thinking beyond the end of your limited experience
isn't your strong point.

I suppose you'd have dozens of different connectors on each channel
input to satisfy your 'military spec' attitude? And dozens of
different cables to go with those?

Sigh, you are more than brain dead. WTF would the military
intentionally shoot themselves in both feet? What part of
'specification' don't you understand? There were three types of
connectors. XLR, terminal blocks and patch bays. Everything except the
magnetic phono circuits and headphone jacks were balanced. Obviously
you know nothing about the reasons the military uses standards.

Trying to idiot proof simple technology is no big deal, till they
breed bigger and bigger idiots who have ego problems.

You certainly know about that.

Its confirmed with every idiotic post you make.

A modern design would use RF on the line to eliminate any possible
hum,

You get hum from DC?

It can be picked up on a DC circuit.

I'd have said it being picked up on the actual audio output to be more of
a problem, wouldn't you? If you ever thought before typing.

Why do you think they use HF AC to power the lamp used in film
projectors, instead of DC?
Its easier to rectify & filter a power source well above the needed
audio bandwidth, than deal with electrical noise is some locations. try
your DC power in places near a substation, where the AC magnetic field
can affect video monitors, or a high power transmitter causes ingression
problems. No circuit is a perfect balance in those situations.

Think you'd be better telling the mic makers that. I'm sure they'd be
grateful for your original thinking. After all they don't have a single
decent engineer between them...

and be high enough that it couldn't interact with the audio.


Given any thought to cable design? And the lengths those often are?
Over a mile is common.

Yawn. At a mile I would look into fiber or an RF link.

You might well look into it. Of course you wouldn't be funding it...

Try running a mile of audio cable in a place with a lot of lighting is
sheer stupidity.

Is this called thread drift? Or just the effects of alcohol?

I had a lightning strike at my last house. It hit the buried phone
cable and vaporized the copper in 1.2 miles of buried, shielded six pair
cable. then it wiped out the subscriber interface circuit for mine, and
15 other houses and destroyed the copper pair back to the central office.

I had a T studio building hit by lightning as well. it blew out
chunks of concrete, and wiped out our computer network, 11 GHz STL and
four C-band LNBs, most of the satellite receivers and the 1A2 telephone
system I replaced a lot of damaged wire.

All with fibre optic I assume? Wouldn't be a problem to one of your
talents.

That wasn't possible with early phantom mics, using tube preamps.

Dunno where you got the idea of *early* phantom mics being tube. If
there were any they weren't in common use. The first mainstream
phantom power mic was the Neumann KM 84. And it wasn't a tube mic.
Previous condenser valve mics used individual power supplies via
multicore cable. With all the problems that caused in a large rig.

The same tube preamps that like to break into oscillation at times,
or became microphonic.

I suppose you only came across broken ones. In practice, oscillation
was rare. With good makes, of course.

There are some records that were released with the mics acting up.

All of them?

Of course, you don't know what I'm talking about.

I doubt if even you do.

--
*I'm not being rude. You're just insignificant

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Dave Plowman (News)]

In article <mc97u4l1mb2eqbber81mbhvqag6suc1c2a@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:

On Mon, 13 Apr 2009 09:14:18 +0100, "Dave Plowman (News)"
dave@davenoise.co.uk> put finger to keyboard and composed:

In article <8aa5u4dkkdcf9m7tobqdaqgo3h3caa908c@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:

That said, I'd always used the terms "phantom power" and "bias"
interchangeably, but my knowledge of microphones is essentially zero.

Anywhere that sold phantom powered mics would require you to know what
they were when buying, otherwise you might end up with one which didn't
work to your requirements.

I confess I'm ignorant about professional audio gear. I've always
thought of phantom power as a generic term, and it appears that many
people do likewise.

Seems there may well be lots of people who use the term without knowing
what it means.

In fact the Wikipedia article recognises this:

=====================================================================
The low-current 3 to 5 V supply provided at the microphone jack of
some consumer equipment, such as portable recorders and computer sound
cards, is sometimes called "phantom power."
=====================================================================

Yes. Wonder who added that to the original article?

I can see a parallel in the definition of USB standards:
http://www.usb.org/developers/packaging/:

=====================================================================
Because the USB 2.0 Specification encompasses all USB data transfer
speeds, low (1.5Mb/s), full (12Mb/s) and high (480Mb/s), it is
important that vendors clearly communicate the type of product on
packaging and in marketing and advertising materials. Inconsistent use
of terminology in combination with the existing general misconception
that USB 2.0 is synonymous with Hi-Speed USB ... creates confusion in
the marketplace.
=====================================================================

One would think that low, full, and high speed are loose, generic
terms, but in the USB context they have particular numbers associated
with them.

Not sure it's quite the same. There is some compatibility in certain
combinations between the various USB devices. There is none between line
and phantom power.

The funny thing is that telephones can be considered to be phantom
powered, yet I'd never heard the term used in that context until I
read the Wikipedia article on the subject.

No - telephones are line powered. True phantom power was however first
used in the telephone industry for other purposes.

A telephone line is balanced - but if you apply an AVO to that line
you'll see the DC. Do the same to a balanced mic line with phantom
power present and you won't.

OK, I see now ...

http://www.mediacollege.com/audio/phantom-power/

That's not the best of explanations. Phantom power is distributed from a
central PS to the mixer inputs via standoff resistors. Which limit the
amount of current available to any single mic. Necessary to prevent a line
or mic fault bringing down the entire supply.

--
*If you can read this, thank a teecher

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Eeyore]

David Nebenzahl wrote:

Eeyore spake thus:
David Nebenzahl wrote:

In both cases the DC to power the mike's electronics is carried on the
signal line. Looks, sounds, smells like phantom power to me.

It's not TRUE phantom power. True phantom power requires a balanced signal. Read
it up. I've been trying to be practical and helpful and all you can do is bitch at
me. Go learn some FACTS !
http://en.wikipedia.org/wiki/Phantom_power

Ah, the beauty of Wikipedia, the "encyclopedia" any junior-high-school
idiot (or electronics engineer with an axe to grind) can edit. Looking
at that article's revision history, one sees an awful lot of editing by
"anonymous IPs"; what are the chances that one of those is *you*, eh?

If you don't understand the above don't bother coming back to whine at others.

Ah, there it is: now you're stooping to throwing insults. By "you don't
understand", of course, you mean "you dare to disagree with my version
of things".

So let's see what others have to say about "phantom power", shall we?

Irrelevant. The term is regularly abused. I have explained in considerable detail why
it's a no-go and still you whine.

Graham

 

[Eeyore]

Franc Zabkar wrote:

There are other systems where power is supplied to the remote device
via the signal cable, eg a masthead amp, or a video camera, or an LNB
for a satellite dish. I think these are generally referred to as being
*line* powered.

That is the term I would use too. It is NOT phantom power'.

Graham

 

[Eeyore]

Franc Zabkar wrote:

On Mon, 13 Apr 2009 09:14:18 +0100, "Dave Plowman (News)"
dave@davenoise.co.uk> put finger to keyboard and composed:

In article <8aa5u4dkkdcf9m7tobqdaqgo3h3caa908c@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:

That said, I'd always used the terms "phantom power" and "bias"
interchangeably, but my knowledge of microphones is essentially zero.

Anywhere that sold phantom powered mics would require you to know what
they were when buying, otherwise you might end up with one which didn't
work to your requirements.

I confess I'm ignorant about professional audio gear. I've always
thought of phantom power as a generic term, and it appears that many
people do likewise.

In fact the Wikipedia article recognises this:

=====================================================================
The low-current 3 to 5 V supply provided at the microphone jack of
some consumer equipment, such as portable recorders and computer sound
cards, is sometimes called "phantom power."
=====================================================================

Classic 'dumbing down'.

Graham

 

[Eeyore]

"Michael A. Terrell" wrote:

That wasn't possible with early phantom mics, using tube preamps.

I'm not aware of any tube based condensor mics that used phantom power as we
talk of it now. They usually had dedicated multipole connectors rather than the
now ubiquitous 3 pin XLR.

Graham

 

[David Nebenzahl]

On 4/13/2009 3:36 PM Dave Plowman (News) spake thus:

In article <mc97u4l1mb2eqbber81mbhvqag6suc1c2a@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:

I confess I'm ignorant about professional audio gear. I've always
thought of phantom power as a generic term, and it appears that many
people do likewise.

Seems there may well be lots of people who use the term without knowing
what it means.

In fact the Wikipedia article recognises this:

=====================================================================
The low-current 3 to 5 V supply provided at the microphone jack of
some consumer equipment, such as portable recorders and computer sound
cards, is sometimes called "phantom power."
=====================================================================

Yes. Wonder who added that to the original article?

You can easily find out: just check the "history" tab and trace it back.
(But it'll probably turn out to be an "anonymous IP", meaning that it
could be anybody, qualified or not.)

And there's really no such thing as an "original article" on Wikipedia,
as all articles are constantly undergoing rewriting for better or worse
(often the latter).



--
Save the Planet
Kill Yourself

- motto of the Church of Euthanasia (http://www.churchofeuthanasia.org/)

 

[Dave Plowman (News)]

In article <49E3C34C.CF13C6C@hotmail.com>,
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

That wasn't possible with early phantom mics, using tube preamps.

I'm not aware of any tube based condensor mics that used phantom power
as we talk of it now. They usually had dedicated multipole connectors
rather than the now ubiquitous 3 pin XLR.

Rather obvious when you think of the technology then - and the restricted
current available with phantom power.

There's been quite a revival in valve mics and I've a feeling there may be
at least one which runs off phantom. But the majority still use a
dedicated PS and multicore cable.

--
*Never underestimate the power of very stupid people in large groups *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Dave Plowman (News)]

In article <49e3e8a5$0$2720$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

In fact the Wikipedia article recognises this:

=====================================================================
The low-current 3 to 5 V supply provided at the microphone jack of
some consumer equipment, such as portable recorders and computer sound
cards, is sometimes called "phantom power."
=====================================================================

Yes. Wonder who added that to the original article?

You can easily find out: just check the "history" tab and trace it back.
(But it'll probably turn out to be an "anonymous IP", meaning that it
could be anybody, qualified or not.)

And there's really no such thing as an "original article" on Wikipedia,
as all articles are constantly undergoing rewriting for better or worse
(often the latter).

Well you can take it from me the current explanation is pretty decent and
rather better than many others you'll find.

--
*Save the whale - I'll have it for my supper*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.