Schoeps Cmit 5u Issue

[Julian Catz]

Hello 

I own a CMIT 5U (blue version) and I am experiencing an unusual issue that does not seem related to humidity.

The microphone works perfectly when first powered up. However, after being powered with 48V phantom power for some time, it begins producing a repetitive ticking/pulsing noise that sounds like “tf tf tf tf” at a regular interval.

What makes me think this is not a humidity issue is that the problem disappears immediately if I disassemble the microphone body and reassemble it, even without allowing any drying time. The microphone then works normally again, but the noise eventually returns after some time powered by phantom power.

The behavior appears to be temperature-related, as the issue develops only after the microphone has been powered for a while and warmed up internally.

I have tested different XLR cables and recording equipment, and the symptom remains associated with this particular microphone.

Have you encountered similar cases involving:

• thermal-related electronic faults,
• intermittent internal connections,
• solder joint issues,
• or specific components in the CMIT 5U that may become unstable after warming up?

Any guidance would be greatly appreciated.

Thank you very much.

[Scott D Smith]

Julian:

Tough call. It could be related to the some component in the DC-DC converter. Don’t know what else could produce a “ticking” sound, although it’s possible the amplifier circuit could be doing something strange.

Doesn’t sound typical of anything related to the capsule, but can’t rule it out.

 

May have to go back to the mothership.

 

-Scott

[JonG]

Definitely not humidity related. That sounds like a gradual dulling of the sound being captured with eventual sizzley type sounds. I’ve never experienced that with my cmit5u but with the Collettes since they have removable capsules. I have it on good authority that if you keep them clean of dust the effect lessens. 
 

my cmit has that motor boat sound at power up, but otherwise I’ve never had an issue in any weather condition. So yeah it sounds like you should probably send yours in.