How do you tell how dirty your power is?

A scope is the only way to assess the non-60 Hz information on your ac. I doubt if anyone rents them, however. Don't be too certain that ac filtering, etc. while getting rid of some of the noise will sound better. Most such devices hurt the sound more than they help it.

Athipaul, what confirmation is there that lights flashing on the Harvester or noises coming from the Noise Sniffer show noise on your ac line? I agree with your basic advice that if you try a device and like it, why not use it. Again, apart from a dedicated line, most other corrections may harm as well as help ones sound. Often greater quiet comes with less dynamic range. Would it not be great were ones power pure 60 Hz only at 120 volts? Would it not be great were power supplies able to yield pure dc at the desired voltages regardless of what comes in on the power lines?

Guys, I have seen what my ac looks like on a scope, and I have tried many, many devices that are intended to improve your power. The ultimate question is whether the device improves your sound. I worry that measures, such as that with the PS Audio Powerplant's meter, may only capture one aspect of the problems with your electrical service.

I had a Noise Sniffer and many of their active devices that you plugged into circuits that had high noise on them. In each instance when I plugged the device in the noise dropped. I did this until I exhausted the eight devices I had purchased. When I listened to my music, it was quieter and totally uninvolving. I began removing devices near my audio and found the sound improved with each I removed. I thought that surely those in remote locations would have only positive results, but I was wrong. I sold everything. What was the Noise Sniffer measuring, and why was removing it harmful to the life of the music?

I know fullwell that your experiences may differ from mine. I always advise people to let the new improvement settle in for a while and then remove it. If you lose the magic, reinstall it. If you regain the magic, sell the device. I have sold or tried to sell probably 40 such devices over a long career in audio.

Elizabeth, is this tongue in cheek?