MD421 - a little helping hand.

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denmen2000

New member
Joined
Aug 28, 2018
Messages
1
Hey Everyone,  :D

I am new to this forum and every since I got this beautiful MD421 in I really started to like to see if I can repair the mic myself. I made a tuchel-XLR cable myself and noticed the wiring in the mic made a lot of hiss noise so I replaced the wiring, already with great results.

I went to pretty much all the entries for the MD421 on this forum but I couldn’t found my answers.: 

I replaced the wiring and the result is already a lot better. the hiss is gone and no groundnoise is there. I bypassed the filter because it was really hard to re-wire it properly.

I have two questions:
1. the mic is still giving a little humming noise, not like its ungrounded but like the whole XLR cable is picking up sounds (When I gain the mic ith 10 db extra, the sound reminds me of a cheap mic directly putting into a PC without a descent audio interface, (electromagnetic sound)). I would want to know if this is the best I can get out of the mic or if there is something I did wrong. I attached a recording which is done with a descent Apollo interface. The signal also seems to be a little bit low. when I boost the gain to 40db. a 12” acoustic recording is still low.

listen example
https://www.icloud.com/iclouddrive/06th1YQCz6heJAtovF3Caqsbw#MD421.mp3

2. There is the little metal wire sticking out of the top of the diaphragm. is this the way it should look like or is this maybe causing the way it sounds? 



somewhere in this treath
https://groupdiy.com/index.php?topic=57238.msg888816;topicseen#msg888816

whoops posts

- Diaphragm has metal dust or metal particles on top  is this the case?

Thank you so much for your help :).
 

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The photo you posted is not of the diaphgram but of the complete capsule.

The Black plastic part on top with a coil it's the humbucking coil and it's there to reduce noise.
The capsule is underneath that, but don't try to reach it or dismantle it, you can damage the capsule for good.

In the middle of the black round plastic there's some metal piece, like parte of a restor leg or something, clean that out.

If you are having noise while testing the mic without the grille and the mic completely assembled thats normal, the Metal Grille protects the capsule from noise interference, so you should test the mic completely assembled.
 
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