Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Yup, I've seen a few. Usually the PSU is finished in that Hammerite styleEeyore <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.
I've amended the entry slightly to make it clearer.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.
Aha! So much for relying on Wikipedia as a reliable source of information."Dave Plowman (News)" wrote:
[someone else] 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.
I've amended the entry slightly to make it clearer.
Maybe these two examples (Method 1 and Method 2, also reproduced atIn article <mc97u4l1mb2eqbber81mbhvqag6suc1c2a@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:
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.
It's fine. But the Wiki piece gives a good description for those who don'tOn Mon, 13 Apr 2009 23:36:55 +0100, "Dave Plowman (News)"
dave@davenoise.co.uk> put finger to keyboard and composed:
In article <mc97u4l1mb2eqbber81mbhvqag6suc1c2a@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:
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.
Maybe these two examples (Method 1 and Method 2, also reproduced at
the epanorama site) explain it better:
http://www.uneeda-audio.com/pzm/pzm_ch.htm
The same DC current flows from hot to ground, and cold to ground.
Therefore the current flowing between hot and cold is zero.
Franc--thanks for taking the trouble to draw this out. I've been lookingThe supply for each of the L and R microphone inputs is derived from a
buffered, zener regulated 2.6V source. The series resistor is 7.5K.
For comparison purposes, the condenser elements within Sony's ECM-737
mike are each powered from a 4.8V supply via 10K resistors.
I thought that the OP may be measuring the voltage while the mike was
connected, but it appears that 2.8V was the O/C voltage of the
Walkman.
This is the relevant section of the circuit:
2.6V |-- 7K5 --> L
IC201 | |
5.9V o--- R ---+---------+---- buffer -+- 1K ----+---|
| | | |
ZD --- 220uF 47uF --- |-- 7K5 --> R
HZ3ALL | --- ---
_|_ _|_ _|_
= = =
Go and take a look. I am a registered contributor.On 4/14/2009 4:58 AM Eeyore spake thus:
"Dave Plowman (News)" wrote:
[someone else] 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.
I've amended the entry slightly to make it clearer.
Aha! So much for relying on Wikipedia as a reliable source of information.
Correct. Hence minimising any noise contribution from the phantom PSU. HavingOn Mon, 13 Apr 2009 23:36:55 +0100, "Dave Plowman (News)"
dave@davenoise.co.uk> put finger to keyboard and composed:
Franc Zabkar <fzabkar@iinternode.on.net> wrote:
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.
Maybe these two examples (Method 1 and Method 2, also reproduced at
the epanorama site) explain it better:
http://www.uneeda-audio.com/pzm/pzm_ch.htm
The same DC current flows from hot to ground, and cold to ground.
Therefore the current flowing between hot and cold is zero.
Yes, I see you seem to be the entity known as "Pasoundman" there. AndDavid Nebenzahl wrote:
On 4/14/2009 4:58 AM Eeyore spake thus:
"Dave Plowman (News)" wrote:
[someone else] 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.
I've amended the entry slightly to make it clearer.
Aha! So much for relying on Wikipedia as a reliable source of information.
Go and take a look. I am a registered contributor.
Look at pins 20, 21, and 22 of IC101 in the other channel. Pin 20 goesOn 4/11/2009 1:48 PM Franc Zabkar spake thus:
The supply for each of the L and R microphone inputs is derived from a
buffered, zener regulated 2.6V source. The series resistor is 7.5K.
For comparison purposes, the condenser elements within Sony's ECM-737
mike are each powered from a 4.8V supply via 10K resistors.
I thought that the OP may be measuring the voltage while the mike was
connected, but it appears that 2.8V was the O/C voltage of the
Walkman.
This is the relevant section of the circuit:
2.6V |-- 7K5 --> L
IC201 | |
5.9V o--- R ---+---------+---- buffer -+- 1K ----+---|
| | | |
ZD --- 220uF 47uF --- |-- 7K5 --> R
HZ3ALL | --- ---
_|_ _|_ _|_
= = =
Franc--thanks for taking the trouble to draw this out. I've been looking
all over the schematic, and so far I can't find anything to the left of
IC201 in your "drawing" (the 220 uf cap, zener, etc.) Can't see D301 at
all on the schematic. The only zener I can find is one on the DC-DC
board, but nothing there is labled in the diagram. Help!
(I'm not considering modifying the recorder, just satisfying my
curiosity as to how the "plug-in power" works.)
Thanks again for the quick reply.On Tue, 14 Apr 2009 16:08:57 -0700, David Nebenzahl
nobody@but.us.chickens> put finger to keyboard and composed:
Franc--thanks for taking the trouble to draw this out. I've been looking
all over the schematic, and so far I can't find anything to the left of
IC201 in your "drawing" (the 220 uf cap, zener, etc.) Can't see D301 at
all on the schematic. The only zener I can find is one on the DC-DC
board, but nothing there is labled in the diagram. Help!
(I'm not considering modifying the recorder, just satisfying my
curiosity as to how the "plug-in power" works.)
Look at pins 20, 21, and 22 of IC101 in the other channel. Pin 20 goes
to the zener. Pin 20 of IC201 would also go to the same zener,
although it is not shown explicitly because the two channels are
mostly identical (see the note "R-CH is the same as L-CH"). Pin 22 of
IC101 terminates in a capacitor, and is not used (?), whereas pin 22
of IC201 goes to the mike's power circuit and to the LED board.
AFAICT, there is only one zener. It regulates the power for bothOn 4/15/2009 1:26 PM Franc Zabkar spake thus:
On Tue, 14 Apr 2009 16:08:57 -0700, David Nebenzahl
nobody@but.us.chickens> put finger to keyboard and composed:
Franc--thanks for taking the trouble to draw this out. I've been looking
all over the schematic, and so far I can't find anything to the left of
IC201 in your "drawing" (the 220 uf cap, zener, etc.) Can't see D301 at
all on the schematic. The only zener I can find is one on the DC-DC
board, but nothing there is labled in the diagram. Help!
(I'm not considering modifying the recorder, just satisfying my
curiosity as to how the "plug-in power" works.)
Look at pins 20, 21, and 22 of IC101 in the other channel. Pin 20 goes
to the zener. Pin 20 of IC201 would also go to the same zener,
although it is not shown explicitly because the two channels are
mostly identical (see the note "R-CH is the same as L-CH"). Pin 22 of
IC101 terminates in a capacitor, and is not used (?), whereas pin 22
of IC201 goes to the mike's power circuit and to the LED board.
Thanks again for the quick reply.
I'm stumped. I must be making some really dumb mistake. Looking at the
schematic, pin 20 of IC101 (left channel) goes across and down to an
unspecified pin in IC201, connecting to C138 and C305 on the way. I
don't see any zener nor any connection to one. I do see the capacitor on
pin 22 (C132) and how pin 22 of IC201 goes to the mike's power circuit.
D301 is adjacent to C305, at coordinates E15. Right above all threeCan you tell me where (grid coordinates) D301 is? I can't find it at all.
I'm looking at page 19 of the service manual.I'm viewing the schematics in the service manual and its supplement that
you gave us a link to. Am I missing something really obvious here? Or do
you have another diagram?
Ack! No wonder: I was looking at the manual supplement, which omits theOn Wed, 15 Apr 2009 14:47:38 -0700, David Nebenzahl
nobody@but.us.chickens> put finger to keyboard and composed:
Can you tell me where (grid coordinates) D301 is? I can't find it at all.
D301 is adjacent to C305, at coordinates E15. Right above all three
components is a label, "D301 HZ3ALL".
I'm viewing the schematics in the service manual and its supplement that
you gave us a link to. Am I missing something really obvious here? Or do
you have another diagram?
I'm looking at page 19 of the service manual.
As you say, the zener has been deleted from the parts list in theOn 4/15/2009 3:00 PM Franc Zabkar spake thus:
On Wed, 15 Apr 2009 14:47:38 -0700, David Nebenzahl
nobody@but.us.chickens> put finger to keyboard and composed:
Can you tell me where (grid coordinates) D301 is? I can't find it at all.
D301 is adjacent to C305, at coordinates E15. Right above all three
components is a label, "D301 HZ3ALL".
I'm viewing the schematics in the service manual and its supplement that
you gave us a link to. Am I missing something really obvious here? Or do
you have another diagram?
I'm looking at page 19 of the service manual.
Ack! No wonder: I was looking at the manual supplement, which omits the
zener. Like I said, a dumb mistake. Thanks!
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.
In article <J-mdnYIQiM3DHX7UnZ2dnUVZ_vqdnZ2d@earthlink.com>,
Michael A. Terrell <mike.terrell@earthlink.net> wrote:
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'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.
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.
"Dave Plowman (News)" wrote:
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.
I'm no expert on valves, but perhaps a type suitable for a low fi deviceI guess you never saw any of the battery powered tube hearing aids?
They used less power than a mic preamp, due to their directly heated
filaments.
"Dave Plowman (News)" wrote:
In article <J-mdnYIQiM3DHX7UnZ2dnUVZ_vqdnZ2d@earthlink.com>,
Michael A. Terrell <mike.terrell@earthlink.net> wrote:
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.
Then a standard phantom powered mic won't work too well either...Jackass. standardized connectors is a given, in any single setting.
There are places where a common XLR type connector is not suitable, due
to heat, humidity, or vibration.
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.
None of the phantom powered mics I've got hum. That's good enough for me.Sigh. do you always spout such nonsense? Hum can come from anywhere,
not gust the output. Think about that.
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...
No answer, then.Yawn.
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...
Ok, smart arse. Give some costs as regards fibre optic connectors thatOf course I wouldn't. Why would I pay for something the customer
would own? I worked on large projects, where zero downtime was a huge
factor. A mile of fiber is chap, compared to copper when there is no
right of way. It can be lashed to telephone or CATV trunklines, since
it is non conductive. That is a hell of a lot cheaper than digging a
mile long trench 24 to 60 inches deep, and running a mile of 2" schedule
80 electrical PVC, with service vaults every quarter mile. Most
telephone, and all broadband internet around here is fiber optic to less
than two miles for the houses. FIOS may be available in the are in a
few years, where telephone, internet and cable TV come to the house on a
single fiber optic cable. Of course that won't happen in a country
where the post office is in charge of communications. Do they still
bill you, per call on land lines?
Fiber is common as dirt in the US. They even run it to homes for
telephone service, because it is cheaper and more reliable than copper
these days. I keep forgetting that fiber and other advanced technology
isn't available in third world countries.
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?
You patently have no idea about how mics are used in practice. I have, asIf its due to alcohol, then stop drinking. I have never been drunk,
since I don't drink. That just leaves you as the alcoholic. Typical
british BS. You try to slander anyone who won't kiss your stinking ass.
You patently have no idea about how mics are used in practice. I have, as
it's been my career for many a year. So stick to what you do know about
rather than trying to be the resident expert in *everything*. It does you
no favours.
I actually pulled apart a tube hearing aid as a kid. The whole hearing"Dave Plowman (News)" wrote:
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.
I guess you never saw any of the battery powered tube hearing aids?
They used less power than a mic preamp, due to their directly heated
filaments.