Happy New Year!
Hey everyone, it's been quite awhile since I posted.
Yeah, but we haven't forgotten you. Good for us you ran into some trouble. Nah, just kidding. This sucks, of course.But good to see you.
Most likely moisture in the capsule . Try sealing it in a bag with desiccant bags for a few days to absorb and excess moisture.
It could also be dirt in a switch or contamination from fingers or flux somewhere. Leave the mic turned on for a few hours and see if it disappears.
Ha! Good to see some familiar people still here. I'm afraid my interest in DiY mics had to submit to my lack of time over the past couple years. In turn, I wasn't at the forum for awhile. I still have Max's kit for a U47 that I never even opened, as well as an unused CT12 capsule.
You may have a loose connection or a stray piece of solder floating around inside the mic.
Is it Max's full kit with the body? Any chance you'd want to sell it?
Carl if I had to guess I'd say you have some shorts or cold solder joints somewhere in your mics. Try reflowing all your solder and clean the pcbs of any flux to check for solder bridges.