Troubleshooting noisy Mojave Audio MA-201fet condenser mic

[b0b]

Hello everyone!

In times of electronics trouble I have turned to all of you before and received great help which I am truly thankful for. Now it's time again and I hope someone can shed some light on this problem.

I have bought a second hand MA-201fet condenser mic some time ago and only checked quickly that it was working when I first got it. Now it's time to start using it for real and now I noticed that it is really noisy. It takes a little while for it to start after I apply phantom power but then it is like someone would be blowing in to the mic with occasional pops. Could this be caused by anything else than the capsule being damaged in some way? Any tips on what I could do to fix the problem? I have tried all my mic cables and preamps but the problem persists...

any help would be greatly appreciated!

 

[zebra50]

It does indeed sound like a dirty capsule, or, less likely, some dirty component in the high impedance section.

Does the noise get worse if you gently breath into the mic? If so then certainly the capsule is at fault.

If you're happy looking inside the mic then take some photos and post them here!

 

[b0b]

It does indeed sound like a dirty capsule, or, less likely, some dirty component in the high impedance section.

Does the noise get worse if you gently breath into the mic? If so then certainly the capsule is at fault.

If you're happy looking inside the mic then take some photos and post them here!

Thanks for the quick reply! I'll take some pictures when I get home. Couldn't get the grill of yesterday because I didn't have the right screwdriver.

 

[MagnetoSound]

There could be moisture, possibly trapped behind the membrane or otherwise shorting the polarisation voltage. One simple fix to try (if you haven't already done so) is leaving it somewhere very warm and arid for a few days, like inside the airing cupboard. This has worked for me in the past.

 

[zebra50]

It's a good point. Or pop it in a bag with a dry silica gel bag or two overnight.

Often in these cases it'll get better for a bit, then worse again as the salt and saliva on the membrane pick up moisture again.

(I actually built a 'drying chamber' for mics, from an old cigar humidor, with a lightbulb & variac for heat, and silica gel in the humidor trays.)

 

[b0b]

Thanks for all the replies! Really helpfull!

Here's a picture of the capsule.

There's a bit of dust as you can see. Can that little dust cause so much problem?

 

[MagnetoSound]

Can that little dust cause so much problem?

I really wouldn't have thought so.

You could solder a fixed cap in place of the capsule (a 50pF or so polystyrene should be fine) and see if the noise goes away or not. It might just be a noisy FET.

 

[AuralArts]

Ive had some issues with the Mojave ma 300 noise. Ive sent it in three times now. The first two times they replaced the tube, the third they replaced the capsule.. any idea what could be going on?

I have a Manley Ref C that has absolutely no issues in my room.

 

[pucho812]

Ive had some issues with the Mojave ma 300 noise. Ive sent it in three times now. The first two times they replaced the tube, the third they replaced the capsule.. any idea what could be going on?

I have a Manley Ref C that has absolutely no issues in my room.

They told you what they replaced. They found issue. Is it still misbehaving?

 

[pucho812]

Hello everyone!

In times of electronics trouble I have turned to all of you before and received great help which I am truly thankful for. Now it's time again and I hope someone can shed some light on this problem.

I have bought a second hand MA-201fet condenser mic some time ago and only checked quickly that it was working when I first got it. Now it's time to start using it for real and now I noticed that it is really noisy. It takes a little while for it to start after I apply phantom power but then it is like someone would be blowing in to the mic with occasional pops. Could this be caused by anything else than the capsule being damaged in some way? Any tips on what I could do to fix the problem? I have tried all my mic cables and preamps but the problem persists...

any help would be greatly appreciated!

Would have to hear it but I am leaning with smart folks and thinking there is a capsule related issue.
Try and dry it out.