I first had the WD828A: no problem.
Then I DCID to let go for 2 microphones hand: WD828.
Big mistake: the micro greens whistles continuously, it is unusable. Only the red microphone works (very well even).
So I dmand a change in thinking a product deffecteux.
I reu new today: same problem.

Conclusion: trsdu green, red ... happy the problem as they are "insparables" ...