troubleshooting Sennheiser MKH416 shotgun mic

Hello again,

I'm having issues with this microphone. When turned on it will suddenly start making a lot of noise which either disappears by itself, or will stop when the mic is tapped lightly at the XLR end.

This is the European t-power version (i.e. 12V instead of 48). The battery operated unit that provides phantom power to the mic (MZA14TU) delivers a steady 12.6 volts so I don't see that being the issue. 

I figured I'd post here to see if anyone has some experience with this issue or microphone before I send it over to Sennheiser where they'll probably overcharge me just to replace a cap. I'd appreciate any help/tip/advice.

Following is a link of the noise the mic makes taken from a file I recorded:
https://dl.dropbox.com/u/18935229/test%20sennheiser%20noise.mp3

Thanks in advance for your help!

Cheers

That's a horrible noise coming from such a great microphone.  I may not be able to sleep at all tonight! 

Seriously though, have you tried lots of other cables that you know work?  If so, disassembling the xlr connector in the mic itself may be easy and show a skectchy connection....

Hmm, my feeling is a sketchy connection would make more of a scratchy kind of sound whereas this is almost like a distorted sucking sound that crescendos then vanishes. My intuition tells me it's a component based problem though I have absolutely no experience with mics and very limited knowledge of electronics  so have very little to base myself on.

As far as the quality of the mic, agreed, very nice sounding. Can also work great as a voice-over microphone depending on the voice.

Those mics use an oscillator as the amp, so something is out of whack there. Probably a loose connection, or a bad cap, or if its anything like my MKH804 or MKH404 you could try carefully adjusting the variable inductors to properly "retune" the oscillator section. They sound great!

But if there was something out of whack wouldn't the noise be constant? In my case it's intermittent, the issue sometime not manifesting itself at all throughout a recording session. Could it be a cold solder that gets "aggravated" through manipulation? Do you - or anyone for that matter - have a schematic where the potentially problematic* part of the circuit could be pointed out?

*no pun, or quadruple alliteration, intended...

Ok sorry, should've listened to your clip first that does NOT sound like oscillator troubles. Definitely check your power supply/connectors etc for anything suspect. Sounds like a loose connection (like musika was saying)


But upon second listen, what is the "noise" you are talking about? is it the white noise in the background, or that banging noise? I would assume the banging was you tapping on it, and the white noise is your problem. If so that is probably coming from the oscillator. If its that banging rustling noise, loose connection.

Sorry for being confusing!

abechap024 said:

... or if its anything like my MKH804 or MKH404 you could try carefully adjusting the variable inductors to properly "retune" the oscillator section.

Click to expand...

DON'T DO THAT!  You have no way of getting it right that way and are certain to misalign the mike!

I think its a bad solder joint or connection.

I own several of these mics a couple of which have had similar noise.  The problem turned out to be an intermittent internal ground-to-case connection.
Best,
Bruno2000

ricardo said:

abechap024 said:

... or if its anything like my MKH804 or MKH404 you could try carefully adjusting the variable inductors to properly "retune" the oscillator section.

Click to expand...

DON'T DO THAT!  You have no way of getting it right that way and are certain to misalign the mike!

I think its a bad solder joint or connection.

Click to expand...

Haha yes, its not for the faint of heart. Yes there is no calibration procedure that I know of, though I got some very usable results from mine..

bruno2000 said:

I own several of these mics a couple of which have had similar noise.  The problem turned out to be an intermittent internal ground-to-case connection.
Best,
Bruno2000

Click to expand...

Hi Bruno,

How did you resolve that?