Just picked up the iso-max ci-2rr. I have not installed it in my X yet.. I also picked up one for my home system. Wow this is a really high quality little box! At home my amp and pre-amp are separated by about 20 ft. Even though they are wired to the same dedicated circuit I was having a ground-loop problem. Currently, I've had to float the electrical ground on one side to eliminate the loop. Now with the ISO max I can ground both pieces of equipment. My home amplifiers are conrad-johnson tube gear.. I notice no difference in the sound quality (I'm real picky) and I feel much more comfortable that these high voltage amps are now properly grounded. Now to try the other one in the X. Once again thanks for the pointer Ken!