Aug 13 2011
How to Resurrect a u87
A common problem with the Neumann u87 manifests itself with the microphone cutting out when you’re singing right in to it, then coming back to life when you shut up. This only occurs when doing vocals, it’s usually fine on everything else.
The problem is caused by a build-up of dust and dirt on the diaphragm which interacts with the moisture in the breath. This causes a short circuit, making the diaphragm lose it’s charge. As the moisture evaporates, the charge returns and the microphone works normally until breathed on again.
The solution is to very carefully clean off all the crap from the diaphragm.
Now if you search the web, you’ll find lots of so-called “experts” advising that cleaning must only be carried out by a service-centre, or you’ll destroy your mic.
Bollocks. I’ve been in enough studio workshops to know that diaphragm cleaning is a routine procedure. You just have to be really careful.
What you need:
- Distilled water
- A couple of really soft paint brushes (water-colour, not decorating)
- Blotting paper cut into strips with the corners rounded off
- Some relaxing music while you work
Put the distilled water into two small cups and keep one brush for each cup. This is so we can do an initial clean, then use the second, with clean water and brush, to finish off.
Now carefully swish the water over the diaphragm to remove all the built-up crud. The diaphragm is indeed extremely fragile, but if you’re careful you’ll be fine. You don’t have to scrub or apply any downward pressure, just gently swoosh the water around.
If you tilt the capsule to clean the top half first, the water with all the crap in it will flow to the bottom, so you can soak it up with the blotting paper, or simply shake it off with a sharp flick. If you’re using blotting paper, cut it into thin strips and round-off the corners.
Then rotate the capsule and repeat until it’s all clean. Remember to pay special attention to to the clear ring around the edge of the diaphragm, as this is where the short-circuit occurs.
It is as simple as that. Give both diaphragms a good wash with the first cup of water, then do it all again with the clean water and brush.
When you’re done, stick the capsule on the window-sill in the sun to dry out completely, then put your mic back together.
Here’s my mic, before and after:
-
- u87 Before
-
- u87 After
