arcaxis
Well-known member
I don't remember how half my old mics sound and maybe some may sound better on the newer gear I have, so I've pulling out a few to give a try. Bought this AT MB4000c back in the late 90's as it would run off an AA battery for the old Fostex 4 track cassette deck that had no phantom power. Plugged it into the mixer last night and right off I heard a light hum. Touch the headbasket and it got markedly worse. Scraped a small amount of paint from the basket frame and ohmmed it out back to the pin 1 ground of the XLR connector.... infinity/open circuit. Carefully removed the mylar label around the body and some seepage of contact cement was visible near the slip joint where the headbasket assembly connected. I have no idea if internally a ground was somehow attempted to connect the body to the headbasket or AT relied on the metal making contact. To get the headbasket semi-connected to the body I ran the blade of an Exacto knife around the slip joint seam to abrade the aluminum and this seemed sufficient to get my resistance reading down to zero. The mic now has zero hum and sounds pretty good for a not expensive mic.
