A Service Bulletin has been issued on the Audio-Technica BP4025 and AT8022 Stereo Microphones.
Due to a production wiring error, the output of both channels of some of these microphones is out of phase with industry convention. The microphones exhibit no problems when used individually; their problems occur when used together with other microphones.
Audio-Technica will repair affected microphones at our expense.
Please contact the Audio-Technica service department at (330) 686-2600 or firstname.lastname@example.org for instructions on how to return your BP4025 and AT8022 microphone(s) for repair.
Identifying Affected Microphones
This Service Bulletin applies only to BP4025 microphones identified with any of the following date codes: 0844, 0850, 0851, 0852, 0904, 0907
The BP4025 date codes are located on a sticker attached to the XLR connector at the bottom of each microphone. Note: If your BP4025 microphone’s date code is marked with a green dot, or is a different number from the numbers listed above, it does not require service.
This Service Bulletin applies only to AT8022 microphones identified with any of the following date codes: 0840, 0843, 0848, 0904, 0909, 0921
The AT8022 date codes are located on a sticker inside the microphone’s battery compartment. Note: If your AT8022 microphone’s date code is marked with a green dot, or is a different number from the numbers listed above, it does not require service.
Please know that we profoundly regret this error and are very sorry for any inconvenience to you.
This Service Bulletin was posted on July 28, 2009.