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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

Showing 1 response by three_easy_payments

three_easy_payments's avatar
three_easy_payments
2,097 posts
 
I used a $20 meter and could tell that my voltage was fluctuating quite a bit during the day which was also moving the bias on my power tubes quite a bit.  I ended up trying a PS Audio regenerator and they gave me a 30-day return period if I didn't like it.  I discovered the THD on my line was at times over 4% and the unit brought it down to less than 0.1% while also blocking nearly all DC that might be on the line.  The regenerator substantially improved my sound quality and also massively reduced the noise floor on my SET amp while also providing electrical spike protection.

Here's a screen shot from a few moments ago of the display.  You can see it's taking the incoming 3.8% THD this evening and dropping it to 0.1% while also correcting the voltage to 120V and keeping it there.  My tube bias never wanders at all now and the system sounds fantastic.  I have no SQ fluctuations over a 24 hr period anymore and all my gear is plugged into it.  I'm not a huge fan of PS Audio gear other than their regenerators - this is what they really got right IMO.

https://i.postimg.cc/MKQR7Nqm/Screen1.jpg
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