Foghorn, an alternative, which may be better because it's on duty all the time, and gives you shut down time, in event of a power loss, is the battery back ups.
A battery back up cleans the signal brought in and I've seen an instant improvement in computer performance when I ran one in some areas, crashes dropped to zero-ish.
Essentially, a good one will feed your electronics off a battery, the output which is converted to usable watts (amps x volts), so their output is smooth and steady.
They also isolate you sensitive equipment from surges.