Just wanted to share a LOL moment . . .
Bought a M-10 a few months ago. Love it. Retired the trusty JB3 after about a decade of service in the field. Running AKG 481/3 > Oade m-248 > GAK interconnects > M-10.
First time out, I was running in a pair of ceiling mounts, spaced about 25' and each equidistant to the PA stacks at our local venue. I noticed immediately that the left channel was much stronger than the right (or the right was much weaker than the left). I compensated with the Oade by adjusting the gain knobs accordingly and recorded the show. Back at home, I read all of the M-10 threads to see if this was a common/uncommon problem. Saw some similar issues, but hoped that I didn't get a bad unit.
Next time out, same thing only with the different channel. Frustrating.
Third times a charm. In setting up for the third outing, I happened to take a look at the filter switch on one of the mics - lo and behold, it had somehow gotten switched to low. I've never, ever touched them. Changed it back to zero (0). Miracle upon miracles, both left and right channels were happily paired.
Problem and mystery solved.
Game on.