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#1
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Sennheiser MKH 816T Question
Greetings all,
A coworker came to me with a question I can't answer. I'm hoping someone here might be able to help. We have an old Sennheiser MKH 816T shotgun mic in our production cabinet. These mics use the older type of phantom power--12 volt T. Now, I do know they are not compatible with traditional 48 volt phantom--unless the proper adapter is used. I'm also guessing plugging one into a 48 volt supply may damage the microphone. Well...without asking anyone first, my coworker says he went ahead and plugged it into a mixer equipped with 48 volt phantom power to test it. Nothing happened. He then came to me and asked if he might have trashed the mic, by doing this? I've never used a mic like this, so I really have no idea of possible consequences. We do not currently have the necessary adapter to covert 48 volt phantom to the 12 volt T type supply, so I can't test it, to see if the mic has been damaged. Anyone here able to comment on the likelihood of the mic being damaged by this? If damage is unlikely, would it be worth ordering the necessary adapter & putting this older mic back into use? Thanks in advance! Mike |
#2
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Sennheiser MKH 816T Question
wrote:
We have an old Sennheiser MKH 816T shotgun mic in our production cabinet. These mics use the older type of phantom power--12 volt T. Now, I do know they are not compatible with traditional 48 volt phantom--unless the proper adapter is used. I'm also guessing plugging one into a 48 volt supply may damage the microphone. Well...without asking anyone first, my coworker says he went ahead and plugged it into a mixer equipped with 48 volt phantom power to test it. Nothing happened. He then came to me and asked if he might have trashed the mic, by doing this? I've never used a mic like this, so I really have no idea of possible consequences. He might have. The problem is that the output blocking capacitors aren't rated for 48V on those, and momentary application of 48V will make them fail. We do not currently have the necessary adapter to covert 48 volt phantom to the 12 volt T type supply, so I can't test it, to see if the mic has been damaged. Anyone here able to comment on the likelihood of the mic being damaged by this? If damage is unlikely, would it be worth ordering the necessary adapter & putting this older mic back into use? You should definitely order or make the adaptor (although note that if you run this off a real T-power supply instead of the phantom-to-T adaptor it will be harder to overload), just so you can see if it's damaged. These mikes will run on 9V so you can put a 9V battery in a Bud box with a couple connectors, a resistor, and some DC blocking caps and have something good enough for test purposes. (It will overload more easily with 9V though). It's a weird microphone but it's a real lifesaver outdoors. You don't see them very often because wireless packs now get used on wide shots where before we would have used a long shotgun, and because they are a pain if you are trying to boom and mix at the same time (and these days we get some poor sod booming, mixing, and operating camera at the same time). But I think they are worth trying. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#3
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Sennheiser MKH 816T Question
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#4
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Sennheiser MKH 816T Question
"Peter Larsen" wrote in message
k... On 25-07-2014 20:35, wrote: We have an old Sennheiser MKH 816T shotgun mic in our production cabinet. These mics use the older type of phantom power--12 volt T. NO, this is important, NO, it is NOT using any type of phantom power. It uses Tonleiter. Because of that you should KEEP the tüchel cabeling standard until the phantom to tonleiter powerconverter that you purchase. Apparently there was a period when these were produced with T12 power and XLR connecters, which is just an accident waiting to happen with all the P48 gear now. For the OP - there's a chance that the mic went into the closet because it didn't work the last time someone tried it on P48. Sean |
#5
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Sennheiser MKH 816T Question
On 7/26/2014 8:56 AM, Sean Conolly wrote:
"Peter Larsen" wrote in message k... On 25-07-2014 20:35, wrote: We have an old Sennheiser MKH 816T shotgun mic in our production cabinet. These mics use the older type of phantom power--12 volt T. NO, this is important, NO, it is NOT using any type of phantom power. It uses Tonleiter. Because of that you should KEEP the tüchel cabeling standard until the phantom to tonleiter powerconverter that you purchase. Apparently there was a period when these were produced with T12 power and XLR connecters, which is just an accident waiting to happen with all the P48 gear now. For the OP - there's a chance that the mic went into the closet because it didn't work the last time someone tried it on P48. Sean Since the 48 volt phantom power is fed through 6.81K resistors, isn't there a good possibility that the voltage actually reaching the electronics is limited and the mic is not damaged? Why wouldn't the 816 have overvoltage protection? |
#6
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Sennheiser MKH 816T Question
mcp6453 wrote:
Since the 48 volt phantom power is fed through 6.81K resistors, isn't there a good possibility that the voltage actually reaching the electronics is limited and the mic is not damaged? It's current limited, and that helps a lot. Does it help enough? Usually, but not always. Why wouldn't the 816 have overvoltage protection? Because it was designed before 48V phantom existed. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#7
Posted to rec.audio.pro
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Sennheiser MKH 816T Question
"mcp6453" wrote in message
... On 7/26/2014 8:56 AM, Sean Conolly wrote: "Peter Larsen" wrote in message k... On 25-07-2014 20:35, wrote: We have an old Sennheiser MKH 816T shotgun mic in our production cabinet. These mics use the older type of phantom power--12 volt T. NO, this is important, NO, it is NOT using any type of phantom power. It uses Tonleiter. Because of that you should KEEP the tüchel cabeling standard until the phantom to tonleiter powerconverter that you purchase. Apparently there was a period when these were produced with T12 power and XLR connecters, which is just an accident waiting to happen with all the P48 gear now. For the OP - there's a chance that the mic went into the closet because it didn't work the last time someone tried it on P48. Sean Since the 48 volt phantom power is fed through 6.81K resistors, isn't there a good possibility that the voltage actually reaching the electronics is limited and the mic is not damaged? Why wouldn't the 816 have overvoltage protection? As Scott said - it was designed before P48 was a consideration, so it's just a matter of how much over-voltage the designers thought was prudent - 2x, 4x .... ? Plus one of the pins with 48v is supposed to be a ground for the 12v, so it raises the possibility of reverse biasing a component somewhere, depending on what they did with pin1. Just speculation on my part, but enough that I wouldn't want to take bets on the results. Sean |
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