Hello,
My friend sent me his AT4040 mic for an attempted repair. While I've successfully built a couple of quality condenser mics, I've never done any troubleshooting on a faulty one. The claim was that the mic was simply no longer outputting any sound at all. After opening it up and giving it a visual inspection I checked for continuity between the pcb and the capsule. To my surprise, the resistance to the capsule measured less than 2 ohms. I was always under the understanding the the diaphragm and backplate were physically separated, as in a capacitor. This mic appears to be a fairly standard cardioid only mic, which I believe would be a single membrane and a backplate.
Is there anyone that is familiar with the expected straight DCR resistance of a capsule as found in the AT4040? I did disconnect one of the capsules leads from the board to make certain I was looking at the capsules resistance and not the pcb circuit. So yeah, 2 ohms across the 2 leads that connect to the capsule.
thank you!
Best,
Phil Donovan
My friend sent me his AT4040 mic for an attempted repair. While I've successfully built a couple of quality condenser mics, I've never done any troubleshooting on a faulty one. The claim was that the mic was simply no longer outputting any sound at all. After opening it up and giving it a visual inspection I checked for continuity between the pcb and the capsule. To my surprise, the resistance to the capsule measured less than 2 ohms. I was always under the understanding the the diaphragm and backplate were physically separated, as in a capacitor. This mic appears to be a fairly standard cardioid only mic, which I believe would be a single membrane and a backplate.
Is there anyone that is familiar with the expected straight DCR resistance of a capsule as found in the AT4040? I did disconnect one of the capsules leads from the board to make certain I was looking at the capsules resistance and not the pcb circuit. So yeah, 2 ohms across the 2 leads that connect to the capsule.
thank you!
Best,
Phil Donovan