AKG C451 w/ CK1 capsule getting periodic low frequency noise

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ethervalve

Well-known member
Joined
Nov 19, 2008
Messages
210
Location
Montreal
Hi all,
My C451 developed a bit of an issue a while back where it sometimes gives off a 'whomp whomp whomp' low frequency noise (like low frequency self-oscillation) in bursts every few seconds. The issue is a bit tricky to troubleshoot as it seems to go away whenever I want it to appear for testing (only to reappear on an important drum track!).
Could this be related to humidity? Something else?
Thanks in advance for any hints.
 
Most likely moisture and/or contamination in or around the capsule (including the area around the contact pin inside the mounting thread) causing intermittent discharge of the polarising voltage.

 
thanks Dan! I'll give the contacts a cleaning and pack the mic away with some desiccant. That's quite interesting, that discharge of polarizing voltage bit. I've had moisture problems with a couple other condenser mics (Montreal gets humid) but they either cut out completely, crackled, or developed a thin sounds.
 
CK1 capsules aren't necessarily known for their longevity.  If you can fix it, you might want to send it here:

http://www.akgmicrepair.com/

He was the AKG North American repair guy until he went out on his own, and I've only read good things about his service.

Cheers,
--
Don
 
i have the exact same issue with a CK1, in my case capsule is shot....
did you open the capsule to see the diaphragm?
in my capsule you can see that all the (circular) edge of the diaphragm is faded...
 
idylldon said:
CK1 capsules aren't necessarily known for their longevity.  If you can fix it, you might want to send it here:

http://www.akgmicrepair.com/

He was the AKG North American repair guy until he went out on his own, and I've only read good things about his service.

Cheers,
--
Don

He did some work on a couple 451/CK1's I got on ebay  acouple years before he split off (  I think AKG closed that facility )  he did great work , old parts returned with repaired mics and still in service.

 
 

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