Hello to all!
Recently I have been given for repair an AKG P220 microphone and it has a peculiar failure, my client told me that it didnt not work.. i ran some tests, apparently it works but if I say something very loudly right into the capsule screen, the output sound goes totally off and then very slowly recovers back, sometimes with what sounds like a very random low-passed noise. I am wondering if the capsule is damaged somehow and goes out of spec of the rest of the circuit after receiving a stronger acoustic shock (a loud shout right into the mic) or the failure is part of the circuits.
I have an AKG P420 mic at hand and it does not behave like this, the output never goes dead no matter the level of sound close to the screen.
I tested the P220 with a cheap Phonic console I have here (which measures around 51V on the phantom lines unconneted to the mic) and it behaved like this when strong levels of sound are produced right at the capsule. I left it laying on a table without touching it recording the room ambience for 4 hours and it did not fail once.
After testing I gave it back to my client who tested it with a Tascam computer interface, as well as with using an external phantom power supply and he reported back that the sound goes out/off periodicaly, kinda randomly and back on, so no stable correct operation.
The P220 mic is the black model with entirely surface mount components on the boards. The mic is out of warranty so mostly its up to me to figure out how to repair it.
I have a Neumann mic at hand and I was thinking of swapping the capsule with the AKG to see if that will indicate if the problem resides in the capsule or the circuit, but still have to try it.
Any advice would be greatly appreciated.
Best regards,
Konstantin
Recently I have been given for repair an AKG P220 microphone and it has a peculiar failure, my client told me that it didnt not work.. i ran some tests, apparently it works but if I say something very loudly right into the capsule screen, the output sound goes totally off and then very slowly recovers back, sometimes with what sounds like a very random low-passed noise. I am wondering if the capsule is damaged somehow and goes out of spec of the rest of the circuit after receiving a stronger acoustic shock (a loud shout right into the mic) or the failure is part of the circuits.
I have an AKG P420 mic at hand and it does not behave like this, the output never goes dead no matter the level of sound close to the screen.
I tested the P220 with a cheap Phonic console I have here (which measures around 51V on the phantom lines unconneted to the mic) and it behaved like this when strong levels of sound are produced right at the capsule. I left it laying on a table without touching it recording the room ambience for 4 hours and it did not fail once.
After testing I gave it back to my client who tested it with a Tascam computer interface, as well as with using an external phantom power supply and he reported back that the sound goes out/off periodicaly, kinda randomly and back on, so no stable correct operation.
The P220 mic is the black model with entirely surface mount components on the boards. The mic is out of warranty so mostly its up to me to figure out how to repair it.
I have a Neumann mic at hand and I was thinking of swapping the capsule with the AKG to see if that will indicate if the problem resides in the capsule or the circuit, but still have to try it.
Any advice would be greatly appreciated.
Best regards,
Konstantin
