Gefell M94 capsule weirdness

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

mylesgm

Well-known member
Joined
Feb 21, 2009
Messages
831
Location
melbourne, Australia
Hi all,

I've got three m94 caps, 692 bodies and 1 691 body.  Up until yesterday everything was working fine.  Today I set them up for a recording only to discover (after extensive testing) that 2 of the m94 caps had failed and now output no audio.  I used them yesterday at a location recording without issue took them home and then this morning took them out to a different studio and as I said two of the three caps no longer work.  What could cause this failure?  They were not dropped and they did not get wet.  I'm at a loss to explain what has happened...
 
i've had way more issues with bodies than capsules in this series - the switches on the 692 typically, the odd tantalum making noise....but on the caps I'd make sure they aren't loose feeling and the bayonet is making proper contact with the body -
 
mylesgm said:
I'm at a loss to explain what has happened...
I would think some humidity has actually condensed by coming from a warm humid atmosphere to a cool environment.
You could just let the capsules dry in a warm dry climate; they should recuperate in about 1-2 days.
You could also use ether (the ethylic ether you find in pharmacies (drugstores).
Pour some in a small saucer; put the capsule 6 inches from the saucer on  a table; blow lightly on the saucer so the ether vapors will go towards the capsule. The ether vapor has the property of attracting humidity. This may take just a few minutes compared to hours for natural drying.
This is what we did at Barclay Studios with the KM54's when we had this problem.
 
Thanks for the responses!

Well I have several capsules, 2x m70, 2x m93 and 3x m94 and they travel with me as a kit and hence have been exposed to the same climate controls.  They've also been sitting in a warm, dry studio since for two days and only the two m94 capsules exhibit this issue.  They are so dead that they might as well not be plugged in.  I'll keep trying them from time to time to see if they are drying out but could there be some other issue?
 
Typical for the M94 (and M70) are that they over the years getting small holes in the nickel
membrane but still works to a certain content, eventually a piece of the detoriating membrane
touches the backplate and the capsule is "dead".

Maybe a test with a DMM could reveal if its like that in your case, visual inspection
is difficult and involves disassembly of the capsule. (at your own risk...)

 
 

Latest posts

Back
Top