A line conditioner can add consistency to a sound system for sure.
If anyone in Canada wants to try a good 'cheapie' one, find a dealer in your area that carries the Technicontact ones. They have a power strip with audible alarm, RF noise suppression, ins and outs for phone and coax and space to fit wall warts too. The model is called PA22 and sells for about $60.00CAN.
I have all my audio gear plugged through it, except my power amp, and most pleased with what it does for so little.