Hi,
I just got this idea for suppling the ECM8000 with power without using
a mixer, external phantom power supply or preamp as a go-between.

Here is the setup:
ECM8000 (XLR output/jack) SoundCard (with XLR input/jack)
-------------------------------------------
^
|
(here is where I'd like to insert phantom power to power the mike)

Is it possible to insert phantom power in between the two connectors.
Without causing damage to the Soundcard and perhaps only using
batteries as a source of power.

Does anyone out there know what I would have to do to get this right?
A schematic for this kind of thing would be ideal. (assuming it is
possible)

Thanks.
Witek.

"Witek" wrote in message
om
Hi,
I just got this idea for suppling the ECM8000 with power without using
a mixer, external phantom power supply or preamp as a go-between.

Here is the setup:
ECM8000 (XLR output/jack) SoundCard (with XLR input/jack)
-------------------------------------------
^
|
(here is where I'd like to insert phantom power to power the mike)

Is it possible to insert phantom power in between the two connectors.
Without causing damage to the Soundcard and perhaps only using
batteries as a source of power.

Does anyone out there know what I would have to do to get this right?
A schematic for this kind of thing would be ideal. (assuming it is
possible)

It's possible. You can buy products that do this for a reasonable price.

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:

http://www.google.com/groups?selm=Ap...%40comcast.com

If you have any questions about it, please ask them here.

"Witek" wrote in message
om
Hi,
I just got this idea for suppling the ECM8000 with power without using
a mixer, external phantom power supply or preamp as a go-between.

Here is the setup:
ECM8000 (XLR output/jack) SoundCard (with XLR input/jack)
-------------------------------------------
^
|
(here is where I'd like to insert phantom power to power the mike)

Is it possible to insert phantom power in between the two connectors.
Without causing damage to the Soundcard and perhaps only using
batteries as a source of power.

Does anyone out there know what I would have to do to get this right?
A schematic for this kind of thing would be ideal. (assuming it is
possible)

It's possible. You can buy products that do this for a reasonable price.

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:

http://www.google.com/groups?selm=Ap...%40comcast.com

If you have any questions about it, please ask them here.

"Witek" wrote in message
om
Hi,
I just got this idea for suppling the ECM8000 with power without using
a mixer, external phantom power supply or preamp as a go-between.

Here is the setup:
ECM8000 (XLR output/jack) SoundCard (with XLR input/jack)
-------------------------------------------
^
|
(here is where I'd like to insert phantom power to power the mike)

Is it possible to insert phantom power in between the two connectors.
Without causing damage to the Soundcard and perhaps only using
batteries as a source of power.

Does anyone out there know what I would have to do to get this right?
A schematic for this kind of thing would be ideal. (assuming it is
possible)

It's possible. You can buy products that do this for a reasonable price.

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:

http://www.google.com/groups?selm=Ap...%40comcast.com

If you have any questions about it, please ask them here.

"Witek" wrote in message
om
Hi,
I just got this idea for suppling the ECM8000 with power without using
a mixer, external phantom power supply or preamp as a go-between.

Here is the setup:
ECM8000 (XLR output/jack) SoundCard (with XLR input/jack)
-------------------------------------------
^
|
(here is where I'd like to insert phantom power to power the mike)

Is it possible to insert phantom power in between the two connectors.
Without causing damage to the Soundcard and perhaps only using
batteries as a source of power.

Does anyone out there know what I would have to do to get this right?
A schematic for this kind of thing would be ideal. (assuming it is
possible)

It's possible. You can buy products that do this for a reasonable price.

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:

http://www.google.com/groups?selm=Ap...%40comcast.com

If you have any questions about it, please ask them here.

Arny,

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that lack it.
They are typically composed of a very well filtered 43-48 volt DC power
supply with 2 5.6K resistors and two 50 uF 50 volt (or larger) blocking
capacitors per mic channel served. The 5.6 K resistors are connected, one
from pin 2 of the input jack to the + power supply, and one from pin 3 of
the input jack to the + power supply. The caps are connected from pins 2 & 3
of the input jack to the like pin on output jack. Positive polarity
connected to the input jack, if the caps are electrolytics. There may be 10K
or higher resistors from pins 2 & 3 to pin 1 of the output jack. There may
be 470K or higher resistors connected similarly to the input jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.
2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?
3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the output
jack. There may be 470K or higher resistors connected similarly to the input
jacks.
Why there 'may' be? and also when you say 'or higher', up to how high
a value?

4) This setup you mention wont cause damage to the soundcard?
5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part,
is that standard spec for a cap?

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at (http://www.hut.fi/Misc/Electronics/c..._powering.html)

Could you maybe take a look at it and tell me what you think?
I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.


Thank you very much,
Witek.

Arny,

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that lack it.
They are typically composed of a very well filtered 43-48 volt DC power
supply with 2 5.6K resistors and two 50 uF 50 volt (or larger) blocking
capacitors per mic channel served. The 5.6 K resistors are connected, one
from pin 2 of the input jack to the + power supply, and one from pin 3 of
the input jack to the + power supply. The caps are connected from pins 2 & 3
of the input jack to the like pin on output jack. Positive polarity
connected to the input jack, if the caps are electrolytics. There may be 10K
or higher resistors from pins 2 & 3 to pin 1 of the output jack. There may
be 470K or higher resistors connected similarly to the input jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.
2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?
3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the output
jack. There may be 470K or higher resistors connected similarly to the input
jacks.
Why there 'may' be? and also when you say 'or higher', up to how high
a value?

4) This setup you mention wont cause damage to the soundcard?
5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part,
is that standard spec for a cap?

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at (http://www.hut.fi/Misc/Electronics/c..._powering.html)

Could you maybe take a look at it and tell me what you think?
I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.


Thank you very much,
Witek.

Arny,

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that lack it.
They are typically composed of a very well filtered 43-48 volt DC power
supply with 2 5.6K resistors and two 50 uF 50 volt (or larger) blocking
capacitors per mic channel served. The 5.6 K resistors are connected, one
from pin 2 of the input jack to the + power supply, and one from pin 3 of
the input jack to the + power supply. The caps are connected from pins 2 & 3
of the input jack to the like pin on output jack. Positive polarity
connected to the input jack, if the caps are electrolytics. There may be 10K
or higher resistors from pins 2 & 3 to pin 1 of the output jack. There may
be 470K or higher resistors connected similarly to the input jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.
2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?
3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the output
jack. There may be 470K or higher resistors connected similarly to the input
jacks.
Why there 'may' be? and also when you say 'or higher', up to how high
a value?

4) This setup you mention wont cause damage to the soundcard?
5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part,
is that standard spec for a cap?

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at (http://www.hut.fi/Misc/Electronics/c..._powering.html)

Could you maybe take a look at it and tell me what you think?
I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.


Thank you very much,
Witek.

Arny,

If you want to roll your own, please read this post that I made in response
to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that lack it.
They are typically composed of a very well filtered 43-48 volt DC power
supply with 2 5.6K resistors and two 50 uF 50 volt (or larger) blocking
capacitors per mic channel served. The 5.6 K resistors are connected, one
from pin 2 of the input jack to the + power supply, and one from pin 3 of
the input jack to the + power supply. The caps are connected from pins 2 & 3
of the input jack to the like pin on output jack. Positive polarity
connected to the input jack, if the caps are electrolytics. There may be 10K
or higher resistors from pins 2 & 3 to pin 1 of the output jack. There may
be 470K or higher resistors connected similarly to the input jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.
2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?
3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the output
jack. There may be 470K or higher resistors connected similarly to the input
jacks.
Why there 'may' be? and also when you say 'or higher', up to how high
a value?

4) This setup you mention wont cause damage to the soundcard?
5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part,
is that standard spec for a cap?

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at (http://www.hut.fi/Misc/Electronics/c..._powering.html)

Could you maybe take a look at it and tell me what you think?
I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.


Thank you very much,
Witek.

"Witek" wrote in message
om
Arny,

If you want to roll your own, please read this post that I made in
response to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that
lack it. They are typically composed of a very well filtered 43-48
volt DC power supply with 2 5.6K resistors and two 50 uF 50 volt
(or larger) blocking capacitors per mic channel served. The 5.6 K
resistors are connected, one from pin 2 of the input jack to the +
power supply, and one from pin 3 of the input jack to the + power
supply. The caps are connected from pins 2 & 3 of the input jack to
the like pin on output jack. Positive polarity connected to the
input jack, if the caps are electrolytics. There may be 10K or
higher resistors from pins 2 & 3 to pin 1 of the output jack. There
may be 470K or higher resistors connected similarly to the input
jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.

Yes


2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?

Yes

3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the
output jack. There may be 470K or higher resistors connected
similarly to the input jacks.

Why there 'may' be? and also when you say 'or higher', up to how high
a value?

These parts are there to discharge the blocking capacitors. Bigger
resistors, longer time period to discharge them. More of an aesthetics issue
than a technical performance issue.

4) This setup you mention wont cause damage to the soundcard?

right.

5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part, is that standard spec for a cap?

A 50 uF 50 V blocking capacitor would be an electrolytic or film capacitor
with that particular rating.

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Yes. But 10, take the closest two.

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at
(http://www.hut.fi/Misc/Electronics/c..._powering.html)

See "Phantom power feeding unit for microphone"


Could you maybe take a look at it and tell me what you think?

It's fine.

I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

"Witek" wrote in message
om
Arny,

If you want to roll your own, please read this post that I made in
response to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that
lack it. They are typically composed of a very well filtered 43-48
volt DC power supply with 2 5.6K resistors and two 50 uF 50 volt
(or larger) blocking capacitors per mic channel served. The 5.6 K
resistors are connected, one from pin 2 of the input jack to the +
power supply, and one from pin 3 of the input jack to the + power
supply. The caps are connected from pins 2 & 3 of the input jack to
the like pin on output jack. Positive polarity connected to the
input jack, if the caps are electrolytics. There may be 10K or
higher resistors from pins 2 & 3 to pin 1 of the output jack. There
may be 470K or higher resistors connected similarly to the input
jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.

Yes


2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?

Yes

3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the
output jack. There may be 470K or higher resistors connected
similarly to the input jacks.

Why there 'may' be? and also when you say 'or higher', up to how high
a value?

These parts are there to discharge the blocking capacitors. Bigger
resistors, longer time period to discharge them. More of an aesthetics issue
than a technical performance issue.

4) This setup you mention wont cause damage to the soundcard?

right.

5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part, is that standard spec for a cap?

A 50 uF 50 V blocking capacitor would be an electrolytic or film capacitor
with that particular rating.

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Yes. But 10, take the closest two.

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at
(http://www.hut.fi/Misc/Electronics/c..._powering.html)

See "Phantom power feeding unit for microphone"


Could you maybe take a look at it and tell me what you think?

It's fine.

I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

"Witek" wrote in message
om
Arny,

If you want to roll your own, please read this post that I made in
response to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that
lack it. They are typically composed of a very well filtered 43-48
volt DC power supply with 2 5.6K resistors and two 50 uF 50 volt
(or larger) blocking capacitors per mic channel served. The 5.6 K
resistors are connected, one from pin 2 of the input jack to the +
power supply, and one from pin 3 of the input jack to the + power
supply. The caps are connected from pins 2 & 3 of the input jack to
the like pin on output jack. Positive polarity connected to the
input jack, if the caps are electrolytics. There may be 10K or
higher resistors from pins 2 & 3 to pin 1 of the output jack. There
may be 470K or higher resistors connected similarly to the input
jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.

Yes


2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?

Yes

3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the
output jack. There may be 470K or higher resistors connected
similarly to the input jacks.

Why there 'may' be? and also when you say 'or higher', up to how high
a value?

These parts are there to discharge the blocking capacitors. Bigger
resistors, longer time period to discharge them. More of an aesthetics issue
than a technical performance issue.

4) This setup you mention wont cause damage to the soundcard?

right.

5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part, is that standard spec for a cap?

A 50 uF 50 V blocking capacitor would be an electrolytic or film capacitor
with that particular rating.

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Yes. But 10, take the closest two.

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at
(http://www.hut.fi/Misc/Electronics/c..._powering.html)

See "Phantom power feeding unit for microphone"


Could you maybe take a look at it and tell me what you think?

It's fine.

I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

"Witek" wrote in message
om
Arny,

If you want to roll your own, please read this post that I made in
response to you a couple of days ago:
If you have any questions about it, please ask them here.

thanks for your offer for help, im gonna take you up on that
I looked again at your description of a schematic. (other post)

There are commercial products that add phantom power to lines that
lack it. They are typically composed of a very well filtered 43-48
volt DC power supply with 2 5.6K resistors and two 50 uF 50 volt
(or larger) blocking capacitors per mic channel served. The 5.6 K
resistors are connected, one from pin 2 of the input jack to the +
power supply, and one from pin 3 of the input jack to the + power
supply. The caps are connected from pins 2 & 3 of the input jack to
the like pin on output jack. Positive polarity connected to the
input jack, if the caps are electrolytics. There may be 10K or
higher resistors from pins 2 & 3 to pin 1 of the output jack. There
may be 470K or higher resistors connected similarly to the input
jacks.

Ive sort of redrawn you description as a sketch:

Input Jack Output jack
Pins Pins
50 uF 50 Volt blocking
.-------------------------------------||-----.------ 2
| |
| 5.6 K |
2--------------/\/\/\----. |
| | |
| 5.6 K | |
3--------.--.--/\/\/\----. |
| | | | 50 uF 50 Volt blocking |
| | .-------------------------------------||-.---------- 3
/ / | | |
470K\ \ 470K | / /
or / / (or higher) | 10K or \ \ 10K or
highr\ \ | higher / / higher
| | | \ \
1----.---. | .---.------ 1
|

+ POWER - POWER

If you have any questions about it, please ask them here.

The questions:
1) The input jack, is that the connection to the the mike? just want
to make sure about that.

Yes


2) Im assuming that (- POWER) is connected to pin 1 (GND) ? All ground
the same right?

Yes

3) Why do you say:
There may be 10K or higher resistors from pins 2 & 3 to pin 1 of the
output jack. There may be 470K or higher resistors connected
similarly to the input jacks.

Why there 'may' be? and also when you say 'or higher', up to how high
a value?

These parts are there to discharge the blocking capacitors. Bigger
resistors, longer time period to discharge them. More of an aesthetics issue
than a technical performance issue.

4) This setup you mention wont cause damage to the soundcard?

right.

5) What is a '50 uF 50 Volt blocking' capacitor? Just the 50 Volt
blocking part, is that standard spec for a cap?

A 50 uF 50 V blocking capacitor would be an electrolytic or film capacitor
with that particular rating.

6) In another spec that I've included below, they say that the
resistors must be matched. Does this mean that you got go and buy
several resistors and measure them until you get 2 exact ones (within
a certain tolerance) ?

Yes. But 10, take the closest two.

Sorry if a lot of these questions seem primitive, but I want to be
absoultely sure on these things.

--------------------------------------------------------------
One more thing. I found this design for phantom power feeding a mike
on the web at
(http://www.hut.fi/Misc/Electronics/c..._powering.html)

See "Phantom power feeding unit for microphone"


Could you maybe take a look at it and tell me what you think?

It's fine.

I would appreciate that.
---------------------------------------------------------------


Phantom power feeding unit for microphone

This is a schematic of external phantom power feeding circuit for
those who don't have mixer with phantom power output.

Microphone Mixer
47 uF
HOT (2) ---------+---------||--------------- HOT (2)
|
6k8
|
+--------+------100 ohm---- +48V feed
| |
| === 100 uF
6k8 |
| GROUND (pin 1)
|
COLD (2) ---------+---------||--------------- COLD (2)
47 uF

GROUND (1) ----------------------------------- GROUND (1)

The +48V phantom power feed is grounded to signal ground (pin 1). +48V
voltage can be generated using transformer+regulator, using batteries
(5x9V=45V which is enough), or using a DC/DC converter circuit which
makes well regulated +48V voltage from batteries.

There should be two 12V zener diodes (wired back to back) between
audio wires (HOT and COLD) and the ground to prevent 48V voltage pulse
passing through the capacitors going to the mixer microphone input.

Use 1% accurate resistors for those 6.8 kohm resistors for best hum
and noise elimination.

Obtaining the +48V power supply for phantom power

In mixing consoles the phantom power voltage is usually made using a
separate transformer output or using a DC/DC converter. One example of
such DC/DC-converter circuit can be found at
http://www.paia.com/phantsch.gif (circui diagram of one microphone
preamplifier kit from PAiA Electronics).

If you are operating using batteries then it might be useful to know
that many phantom powered micks will work fine on less than 48v, try
9v and work up till you get good results, 27v would be 3 9v batterys
and a lot simpler than a DC to DC converter. Remeber that some
microphones do not work properly or sound different when run on too
low voltage. Five 9v batteries in series is 45 volts which should be
enough for any phantom power microphone.

If you do use batteries, put a capacitor around them because batteries
do make noise. Filtering of battery noise can be done for exammple by
using 10 uF and a .1 uF in parallel with the batteries. Another option
is to decouple batteries with a 100 ohm resistor and 100uF 63V
capacitor.

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

A picture paints a thousand words, yes they help a lot.

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

Thank you very much for everything,
now I got to go and build this thing

Witek.

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

A picture paints a thousand words, yes they help a lot.

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

Thank you very much for everything,
now I got to go and build this thing

Witek.

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

A picture paints a thousand words, yes they help a lot.

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

Thank you very much for everything,
now I got to go and build this thing

Witek.

http://www.hut.fi/Misc/Electronics/c...g.html#phantom
is just fine. The nice pictures help, no?

A picture paints a thousand words, yes they help a lot.

Also:

http://www.crownaudio.com/pdf/mics/125519.pdf

http://www.new-line.nl/default.asp?i=61

http://sound.westhost.com/project96.htm (figure 2)

Thank you very much for everything,
now I got to go and build this thing

Witek.