Fortunately, my 'fridge doesn't contribute to the line noise, as I'm using very good power cords and conditioners. But for critical nighttime listening, I can hear the audible compressor hum [I live in a small place!], so that gets tuned off, via the breaker box. I also have to shut down the A/C...not too comfortable in the summer desert heat, especially when running a pair of Class A biased tube monoblocks...used in a near-field listening set-up!
