Studio Projects C1 Condenser Mic fading on and off at random

Hi Everybody,

I have been asked to take a look at a Studio Projects C1 condenser microphone which is basically not working correctly. After plugging it in, there is no life. Then it starts to hum and come to life where if you tap the mic it is working. When I speak into it, it gives good quality vocal then it cuts out and dies again. It will remain of for a while and then come back on itself.
I have checked the components on the pcb. All seem good. I’ve went over all the solder joints. All are good.
Has anyone here come across the likes of this before? Could it be the capsule?
I attach a few pics.
I am going to replace the J305 Incase it is not working correctly. I have removed it from the pcb to test it. It seems ok but I might replace it anyway. Other than that I’m in need of a little help.

Kind Regards,
Paul
 

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Chances are the capsule has some moisture in it. I'd recommend allowing the mic to become warm for a while, which should help to evapourate the water. Packing with silica gel packets also helps.

Remember, you should use a pop screen with mics like these, which will help to stop moisture from your mouth getting to the mic capsule.

Chris
 
Chris,
Thanks for your reply. Much appreciated. Heating the capsule up with the heat gun did the trick. It went from no sound at all to full quality audio. It’s actually working very well now. Hopefully it will be ok and last. I’ll keep it in test here for a few days. I didn’t have silica Bags but I did put some loose silica beeds in around the capsule. I know it rattles but it’ll be ok till I get some bags. Do you have any idea how to clean the capsule? This one is very dirty. I haven’t touched it at all. I’m aware it’s extremely sensitive.
Thanks again.

Kind Regards

Paul
 
Hi Paul,

Cleaning of capsules will require a dedicated clean room etc - well beyond most DIYers and professional services (I only work on dynamic capsules). The likes of Neumann, SE Electronics and a few others have such facilities.

I'm glad the heat worked out for you.

Chris
 
Heating the capsule up with the heat gun did the trick.

Sorry to resurrect this thread a year and a half later but I have the exact same issue - how hot did you set the heat gun, how long did you run it, and how close did you get to the capsule? I assume not long enough to reflow the solder and not close enough to damage the capsule, could you describe your technique in detail?

- Joel