I use mine with 2 mics all the time...and all mics are different. 2 condensors, or 1 cond and one dynamic. I've never had a buzz problem, and mine actually sits about 2 feet from a crt monitor. I have no idea what kind of cable quality I have, just stuff I've picked up along the way. I use both cheap, and a bit less cheap mics. I only use 2 mics with a guitar...either mic'ing an amp, or acoustic.
Just my experiences.