Analyzing the power from the outlet
My PS Audio P-10, $3000 used approx. regenerator has a screen showing about 3% distortion and 118.5 volts which it reduces to .1% distortion @ 120.1 V. I can hear the difference and it's worth it to me (I have two.). Because this is a high price to find out, I suggest you borrow one from a friend as I did (they're heavy)-make an appeal here on audiogon- see if you can hear the difference and then ask yourself if it's worth it to you to buy one. Else, I think there is a trial period. While I realize this is a long winded way to say "try it before you buy it...YMMV" it's not at all intuitive otherwise: I live in the Atl. suburbs, a friend in the city has cleaner power! ; a friend in my same neighborhood even has cleaner power (closer to the transformer?). And so, even if you had a cheap, easy way to measure, what would the number mean? You still have to be able to hear a difference (there probably would be some, in any case) and decide if it's significant to you. |
This is a device that can be plugged into a dual-trace O-scope, and will display the high freq noise, on your incoming AC(both line to neutral and neutral to ground): (http://pdf.textfiles.com/manuals/STARINMANUALS/ETA/Manuals/Power%20Probe.pdf) Here's a demo of it's display and the noise on an AC line: (http://www.youtube.com/watch?v=vOO89uHEprM) There are three parts to the demo on Youtube. Of course everyone's AC quality varies, depending on what's connected to the their local source(everything operating on your side of the neighborhood's single phase distribution transformer). ie: In your own home; anything digital that's operating is polluting your AC with very high freq noise. |
The previous discussion to which Lak refers, of essentially the same question, was in this thread, beginning with the post the link opens at. As you'll see, IMO measurements of AC noise, even with sophisticated instrumentation, are unlikely to be helpful. I've seen suggestions to validate the outlet voltage is consistently 120 V with a tolerance of +/- 3 V. Assuming the outlet meets that benchmark, that would, I think, obviate the need for a power regenerator. (At least I think that is the function of a regenerator.)Besides providing a stable voltage, a regenerator will also reduce or eliminate noise and distortion that is present on the incoming AC, since it is what generates the AC that is provided to the components it is powering. Essentially it consists of an oscillator generating a 60 Hz signal (or 50 Hz in some countries) driving a high powered amplifier which in turn supplies that amplified 60 or 50 Hz signal to the connected components, and a power supply which converts the AC from the wall outlet to the DC which powers its own oscillator and amplifier. Although as you may have seen in past threads some people report that the regenerators they've tried seem to cause compromised dynamics or other issues. It's my (limited) understanding that most audio components have a transformer as the first stage from the power input. Doesn't that automatically decouple most of the noise from the power?The bandwidth limitations of the power transformer will significantly reduce the frequency components of the noise that are above a certain frequency. Noise on the incoming AC will also be reduced by filter capacitors and decoupling capacitors that will be present at various circuit locations in the design. It will also be reduced by voltage regulator circuits that are generally used in audio components, other than in the high power stages of most power amplifiers and integrated amplifiers. Finally, it will be reduced by what is known as the power supply rejection ratio of the amplification and other circuit stages which process the audio signal. All of which is not to say, however, that cleaning up the AC power in some manner won't make a difference, to a greater or lesser degree depending on the specific components that are involved. Regards, -- Al |
