you right, you don't need the mic on/off box.
you can mute it on the wireless.
i hope the buzz in the voice come from the big cables and the many solder points.
so i have moded it again.
i have desoldered all the old and the original cables from the pcb, than i have soldered all new cables direkt on the pcb. now it's no extension, no on / off box, no cold solderpoints.
i hope the buzz is now away

and by the way it looks much better than the first mod^^

