U87 slightly noisy & fades out & in by itself

[okgb]

70's ? U87 slightly noisy & fades out & in by itself  [ borrowed from a friend ]
noise is a soft slight wind / crackle sound
just starting research now , any clues tips or hints appreciated tia!

 

[bruno2000]

Dirty capsule......
Best,
Bruno2000

 

[ln76d]

I agree with Bruno2000!

Dirty capsule.

 

[RuudNL]

Yes, I think the same!
(Or high humidity)

 

[mjrippe]

Agreed.  Do a search for "breath test".

 

[poctop]

I agree with Bruno2000!

Dirty capsule.

+1
D

 

[okgb]

yeah I see that now , so ?
clean the capsule
get the capsule cleaned
or replace the capsule [ with a modern cheaper version ]

 

[Whoops]

Yes I also think is humidity in the capsule or dirt, or both.

place it in front of a De-humidifier one or 2 days.
place it in a dry warm place

I was successful in cleaning U87 capsules using this method:

https://www.brownsound.net/cleaning-a-u87-capsule/

Just be gentle, be calm and take you time,
dont brush the capsule with a thick/dtrong brunsh and dont pressure it. use a really soft brush and gently take the dirt away,
it's also useful to use an Lens Cleaner Air Blower

 

[okgb]

Thank you ,  It's  " o.k.  " if I put a foam wind sock on it, confirming it must be the breath humidity
so I'll take my time with that,  thanks for all the replies!

 

[mjrippe]

yeah I see that now , so ?
clean the capsule
get the capsule cleaned
or replace the capsule [ with a modern cheaper version ]

Or replace the capsule with a current production one from Neumann ($$$)

 

[Matador]

Thank you ,  It's  " o.k.  " if I put a foam wind sock on it, confirming it must be the breath humidity
so I'll take my time with that,  thanks for all the replies!

PM tskguy here on the forums:  I believe he can re-skin those original capsules for a fraction of the price of a new one.

 

[Pip]

Based on my experience you need a capsule re-skin to really trust that mic for a session. Sorry! The person I would recommend is Doug Walker he knows Neumann mics and does great work.


Douglas S. Walker, C.E.T.
Walker Microphones
Cambridge, ON, Canada
519-654-0070

 

[Whoops]

I actually followed the methods I posted above and was able to clean 2x U87 microphones that had the same problems decribed here.
This was 2 years ago and the mics are still used everyday in sessions at the studio.
No more problems after the cleaning

Also the place for the microphones also change, they are kept now in a much better place, where there's no humidity