Not Chilli Posted November 25, 2012 Report Share Posted November 25, 2012 hey! I have a 442 mixer, 744t recorder setup but I bought the gear second hand 2 years ago. I have been recording with a rode NTG 3 until recently as I have upgraded to the cs3e. The problem I am having is that I have been through 2 NTG 3s mics in that 2 years and I am worried that maybe the mixer is how blowing the mics over a long period of time? Since I have bought the cs3 e I don't want my mixer killing that mic. So what I was wondering is can an old mixer damage mics? I mainly do creative gigs and tvc and very rarely recording high SPL. I also have np1 setup powering everything. Any thoughts! Cheers, Piotr Quote Link to comment Share on other sites More sharing options...
Mark Posted November 25, 2012 Report Share Posted November 25, 2012 You could start by checking the phantom power voltage supplied by the 442 with a multi meter. Quote Link to comment Share on other sites More sharing options...
Not Chilli Posted November 25, 2012 Author Report Share Posted November 25, 2012 Thank you for the quick reply! I am on set for the next few days so I will hopefully test it soon. I will try and buy a multi meter. Do you think that it could blow a mic over time or is it very unlikely? Quote Link to comment Share on other sites More sharing options...
Not Chilli Posted November 25, 2012 Author Report Share Posted November 25, 2012 Just bought a multi meter from eBay! Should be coming in 5 days. might be a silly question but how would I test the xlr input? Quote Link to comment Share on other sites More sharing options...
berniebeaudry Posted November 25, 2012 Report Share Posted November 25, 2012 read this article: http://www.mediacollege.com/audio/phantom-power/ then set your meter to DC voltage within the range that encompasses 48 volts and meter across the pins noted in the article. If the voltage is over 48 volts then there's an issue. Quote Link to comment Share on other sites More sharing options...
RPSharman Posted November 25, 2012 Report Share Posted November 25, 2012 There's no electronics store in your neighborhood? I'd want to sort this out faster than 5 days. Quote Link to comment Share on other sites More sharing options...
David Waelder Posted November 25, 2012 Report Share Posted November 25, 2012 There is a very high likelihood that one of the camera assistants would have a volt meter that you could use. As Bernie said, you are trying to measure an expected 48-volts so set the range on the VOM meter appropriately. Insert the probes into pins 1 & 2. It doesn't really make much difference which probe goes into which individual pin; one way will yield positive voltage and the other negative but you are looking for 48 volts either way. You may not measure exactly 48 volts. Depending on the calibration of individual machines you may expect to see from about 46 volts to about 49 volts. But it would be worrisome to see a figure that deviates from the 48-volt specification by more than a few volts. Measuring voltage on an unused channel (i.e. no mike plugged in) will give you the equipment output. You may also wish to know what the voltage is while powering a mike and you'll need a Y-adapter to accomplish that. Different mikes will draw down the available voltage by differing amounts but it would be entirely normal to see the voltage unchanged at 48 volts. It would also be normal if you saw a drop to about 35 volts with a mike actually powered. Anything significantly outside that range would be, well, interesting. Worth mentioning to a repair technician. A mixer that gradually degraded a microphone would be outside my experience. I've never heard of such a thing. I've heard of mixers damaging gear when inappropriately powering microphones - that is, supplying 48-volt phantom power to a dynamic mike or supplying T-power to a phantom mike. Even that is a bit unusual. But I've never heard of a mixer gradually degrading a working microphone over time although I suppose it is possible. A final thought - check that you have been providing 48-volt phantom and not 12-volt phantom. The lower voltage will power the mike but the noise floor will be higher and the output less. And, I suppose that continued use at the lower voltage might cause problems. But I expect you would notice that precisely because the output is less. David Quote Link to comment Share on other sites More sharing options...
Not Chilli Posted November 25, 2012 Author Report Share Posted November 25, 2012 Thanks Bernie! I had a quick look over the article and it does clarify a lot of things and when i get the multi meter i will look over it again and check it out! RPsharman I am currently on a gig and had taken my mixer and the NTG 3 to rode when the second one bust. They did some test of the mic playing though my mixer but didnt have the specific equipment to just test the mixer alone but said that it would be very very unlikely that the mixer is killing the mic but i guess since i am on my third NTG 3 then i thought i would post it up here and see if people are having similar problems. I am in the process to have it serviced by John Barry here in sydney to see if they come up with anything but they are not open today. David! thanks heaps for the long feed back as to what i should do. When looking up this problem on google i kept coming up with nothing so i guess that puts a bit of relief on my end. But i will still be checking to see if there is anything just in case. I definitely have the phantom power on 48v so i am confident that its not the problem. I am on an unavoidable gig at the moment so i have to hold out until wed with it but at the moment i am not experiencing any problems. I will definitely do as you say when i get the gear to test it and if i cant get to John Barry soon or before Christmas. When i figure out this problem then i will definitely write about it and tell you how i went! Thanks to everyone who has contributed in this post! You guys are awesome! Quote Link to comment Share on other sites More sharing options...
jwill Posted November 25, 2012 Report Share Posted November 25, 2012 As this discussion goes on, is there any truth that supplying phantom power to a channel that has a mic that doesn't need phantom power, will damage the mic over time? My example: Sd 552, ch 1 & 2 set to line for my lectrosonic 401s',sh 3 4 5 set to phantom, 5 has the 416 and sometimes I use the Mkh 50 in a choral setup or large group. Often when on sports venues we do sitdown interviews so i leave ch 3 &4 on phantom so I can slap on two ecm 77s and not worry about batteries, then when not using lavs I still use ch 3 and an re 50 for standups, the re 50 does not need phantom yet rather than throw switches I leave it on phantom and have not had any issues! JHW Quote Link to comment Share on other sites More sharing options...
jason porter Posted November 25, 2012 Report Share Posted November 25, 2012 I was under the impression that p48 would not hurt a dynamic mic. I used to run many SM48/58's into a mixer with "universal" p48 ON to power a few condensers. Quote Link to comment Share on other sites More sharing options...
David Waelder Posted November 25, 2012 Report Share Posted November 25, 2012 As this discussion goes on, is there any truth that supplying phantom power to a channel that has a mic that doesn't need phantom power, will damage the mic over time? There shouldn't be any problem. In addressing the situation posited by the OP, I was rather casual in my response when I cited examples of situations where a mike might be damaged by inappropriate power. I sought only to acknowledge that there may be circumstances where one might cause harm by using an incorrect setting. In fact, the rationale behind the phantom power design is that the positive current on one leg is cancelled by the negative current on the other so that the mike element does not "see" any current. Ordinarily, one wouldn't cause any harm by running phantom power even when it's not needed. But, one may get into difficulty providing T-power to a ribbon mike (seldom used in location audio). Also, I suppose that running a mike designed to operate on 48-volt phantom might be harmed by continuous operation at 12-volt phantom. I've not heard of it happening but I wouldn't want to guarantee harmless operation with the wrong setting. Feeding phantom power to an RE-50 should not be a concern. David Quote Link to comment Share on other sites More sharing options...
Boomboom Posted November 25, 2012 Report Share Posted November 25, 2012 One thing I noticed in the past, and I have no idea of the electrics voodoo happening there, is that if I forgot phantom power on my 302 and plugged a Senn G2 receiver into that input, that would drain my 302 batteries in a record time. Woosh: no juice. Couldn't tell with a 442/Lectro combo but *that* combination was a batt-buster for sure. Quote Link to comment Share on other sites More sharing options...
Johnny Karlsson Posted November 25, 2012 Report Share Posted November 25, 2012 Couldn't tell with a 442/Lectro combo but *that* combination was a batt-buster for sure. I read somewhere on Lectro's website (or possibly inthe manual) that phantom power could cause their receivers to not work properly. Quote Link to comment Share on other sites More sharing options...
studiomprd Posted November 26, 2012 Report Share Posted November 26, 2012 " and I am worried that maybe the mixer is how blowing the mics over a long period of time? " highly doubtful for many reasons, and there is pretty much no anecdotal evidence of this happening, either. I do suggest some reading up on industry standard Phantom power (wikipedia, etc)... lower phantom voltage is often responsible for improper performance of mic's that require the full 48 VDC, but not for any damage. Although the PH system of powering is designed to be invisible to balanced, floating, dynamic microphones,there are some devices that prefer not to see Phantom power on them, but damage is about unheard of on properly balanced connections, partly because there is no voltage differential across the balanced pair, and the current flow of phantom voltage is limited to extremely low values by reliable, overrated passive components (resistors). Quote Link to comment Share on other sites More sharing options...
RJBerto Posted November 26, 2012 Report Share Posted November 26, 2012 There could be some problems if you are connecting the mic while phantom is engaged if the pins don't make contact at the same time, but I think this is more dangerous to the preamp than the mic and I think the ntg3 has a shorter pin to protect against this... Quote Link to comment Share on other sites More sharing options...
Not Chilli Posted December 3, 2012 Author Report Share Posted December 3, 2012 Hey! So many awesome responses! So Ryan the NTG 3 does have one longer pin for that reason which I read up on. And thanks heaps Mike for the info! I went into John Barry here in Sydney and showed my mixer and he was also saying he had never heard of a mixer blowing out a mic as. He did say that if the faders get damaged it can cause noise in the channel. I will be sending it in for repairs soon enough when a few of the invoices go through! I feel that I can safely say that it does seem to be the unlucky ntg 3. But when I final get this multi reader from eBay then I will let people know if there are any odd things I pick up! But dam that Sanken CS3e sounds good and natural and rejects background noise well! It is really good to have the ntg 3 though as it sounds like ADR when I get in tight! Thanks again everyone! Quote Link to comment Share on other sites More sharing options...
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