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#1
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#2
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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. |
#3
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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. |
#4
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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. |
#5
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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. |
#6
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#7
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#8
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#9
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#10
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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) |
#11
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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) |
#12
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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) |
#13
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Help needed: Inserting Phantom Power between 2 XLR connectors
"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) |
#14
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#15
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#16
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
#17
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Help needed: Inserting Phantom Power between 2 XLR connectors
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. |
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