Electronics 101 question: How to kill power related clicks?

[mojobone]

Resurrecting this thread for a moment in case my new info sparks any new ideas in an electricians heard.

I've noticed that the click/pop only occurs when electric motors are turned on. The fridge, or the ceiling fan. Is that useful info?

PC

That does help narrow it down. Personally, I have a ceiling fan in my space, but it's never used when recording, not even direct recording, because while it's not as noisy as my former computer, it's way noisier than the current one. A UPS prevents surges, not sags, and sags appear to be the problem. As I see it, there are three options, in descending order of expense 1 professional grade voltage regulator with RFI filtering, 2 having an electrician re-route the circuits to separate the offending motors from your recording rig or 3 a beefier power supply for your interface, the last two of which may or may not work, so there we are...