Would the Remote Microphone 4805AV be damaged in any way when it’s used with stereo equipment rather than a cassette recorder?
No. Although the Remote Microphone 4805AV features a 3.5mm jack and a 2.5mm remote start/stop switch jack which was specially designed to be utilized with Califone cassette recorders, it can be used with all stereo and mono audio equipment that features a 3.5mm mic jack. It will not damage the microphone.