I'm suspicious of whether these can handle high SPLs. I ran mine on stage Friday for the Golden Gate Wingmen, and there is audible distortion at times. It was mics > CA9200 (0 gain, so it was just serving as a 9V battery box) > Roland R-05 line in.
I still want to try them at Red Rocks, and I'm guessing behind the sbd at Red Rocks will be lower SPL than on stage so maybe they'll work for that purpose.