Well, I tried to profile again and it wasn't my mic cables, it's the Kemper. here's the deal:
I have my guitar cord going into the Kemper, and the out from the Kemper going to my amp for profiling. When I hook it up to my amp, I get a local AM radio station. LOUD. And if I'm profiling a distorted amp, it's REALLY LOUD.
My cables are good (G&H plugs, Canare GS6 wire). Hooked the Kemper into a monster power conditioner and also the amp I was profiling (Mesa Mark III Coliseum). Amp does not pick up the radio station if I plug a guitar into it, or even a guitar > pedal > amp. if I do a ground lift on the kemper's output, I get a HUGE buzz that is worse than the radio station.
Any ideas? BTW, my home is about 3 miles from the AM station I'm picking up, and it's a 50,000 watt transmitter.
Pete