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How To Do You Measure the Quality of Your AC Power?

What is the best way to measure the quality of the AC power feeding your listening room? Is there a device you can plug into an outlet that will give you the voltage, frequency, the total amount of distortion relative to a perfect sine wave, etc.? Furthermore, how would you measure the ability of your AC main to deliver transient currents?
It seems like there may be a scenario where you could measure your power quality to be excellent but somewhere in the line you could have a loose or poorly made wiring connection which under heavy load (such as powerful bass notes) you could run into trouble with power delivery. In this scenario, an AC regenerator would not help you, or would help very little.

Just curious what methods people have come up with to systematically analyze their power and how they use those measurements to drive buying decisions or repair work, if needed.

Edit: My apologies for the title typo.
128x128mkgus
helomech
1,737 posts
 

 I wonder if my amplifier would sound better without those SMPS’s on the same circuit. I also wonder if they interfere with each other.

Not if your amplifier is competently designed.

Save your money. Power regenerators do absolutely nothing for sound quality unless your components are very poorly designed. You’ll be better off upgrading your system components. When you own good gear you’ll find that distortion on your grid has absolutely no bearing on sound quality. Companies like PS Audio thrive off hawking such garbage because they’ve realized most audiophiles don’t have any clue how their gear works. 
digitalviper's avatar
digitalviper
123 posts
 
use a power plug extreme 
made in china for only 10$
mkgus's avatar
mkgus OP
324 posts
 
Power regenerators do absolutely nothing for sound quality unless your components are very poorly designed.
In my experience, everything is on a spectrum. It’s not binary. Clean power is very, very important. Every time I’ve cleaned up my power in any way, I’ve experienced positive results. The better designed equipment didn’t benefit quite as much as inferior designs. In the end, it’s up to the listener. Does a specific power upgrade provide enough benefit to justify the cost?
erik_squires
16,406 posts
 
I use something very similar to this little gadget since it measures the main and neutral at the same time.

A good indicator of poor or loose wiring is either the main voltage dropping, or the neutral voltage rising.


https://amzn.to/3m0kEzW

Sadly the one I actually use is no longer carried, but you get the idea.
erik_squires
16,406 posts
 
I could never figure out why the load on the two legs has to be balanced, do your electric devices all turn on and off at the same time? There is always going to be an imbalance.


The requirement to be balanced is not to within 0.0001 %, but to avoid severe imbalances, especially at 50% or higher load. Being within 20% is probably OK. This reduces the need for the neutral to be 2x as big, and I believe also has consequences on the transformer.

If you have a 200A service and are drawing 30A you care a lot less.

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