pop noise

hi guys , i live in a old apartment where i have a lot of noise in electrivity , somtimes i can hear loud hum,click and static noise from my speakers .(just some time) i have two set of hifi systems (amps,spakers,dacs) and this happens to both of them. i already added ferrite core to my power...

Just bought a nad m25, which i have hooked up to my onkyo TX-NR717 and it's making a audible pop noise when im turning it of... it's not super loud or anything but i was just wondering if this is something i should be worried about? Is this normal when using power amps? i've never really owned a...