EMI/RFI/Noise Testing of Power Conditioners and Power Cables

Marcus

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Interestingly, Uberbuss from PI group does not only reduce the readings of the outlets on it. It will also reduce outlets parallel to it. I kind of use UberBuss as parallel filters.
That’s absolutely true! In my system Überbuss measured even better in parallel than on the same line.

On the other end, I also used this “EMI detector” in my friend’s system and readings with one very famous line filter were actually worse than without it…
 
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Ron Resnick

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Today I visited a friend who plugs all of his components, including amplifiers, into a PS Audio P10 power regenerator. The displayed noise level with the EM100 plugged into the outlet into which the P10 is plugged was lower than the displayed noise level when the EM100 was plugged into any of the P10's outlets.

Why would this be? This suggests, perhaps, that regenerating AC does not scrape away noise being picked up by the electrical power or the power cord going into the P10, or noise attracted to the P10 itself, or both.
 
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Folsom

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Today I visited a friend who plugs all of his components, including amplifiers, into a PS Audio P10 power regenerator. The displayed noise level with the EM100 plugged into the outlet into which the P10 is plugged was lower than the displayed noise level when the EM100 was plugged into any of the P10's outlets.

Why would this be? This suggests, perhaps, that regenerating AC does not scrape away noise being picked up by the electrical power or the power cord going into the P10, or noise attracted to the P10 itself, or both.

Sounds right. I suspect it probably could improve a very bad AC signal. The EM100 does not have bandwidth for anything near 60hz, and not very high either. However in general my experience was they can't even scrub the tiniest bit of a power cord swap signature.
 

wil

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Sounds right. I suspect it probably could improve a very bad AC signal. The EM100 does not have bandwidth for anything near 60hz, and not very high either. However in general my experience was they can't even scrub the tiniest bit of a power cord swap signature.
I had a PS audio power plant regenerator, I measured it with the EM 100 and it always had a higher reading than the wall outlet. As I understand, the regenerator’s amplifier (like any amplifier )creates it’s own noise.

Interestingly, the people at PS audio I spoke with had no idea this would be the case.
 

Ron Resnick

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This is interesting, wil! So maybe high EMI noise such as that detected by the EM100 doesn't translate into untoward and problematic sonic effects on the sound coming out of our stereos? Is worrying about high EMI readings just audiophile nervosa?

On the other hand it seems to me that a high ambient EMI environment couldn't be doing anything good for the sound coming out of our stereos . . .

It would be interesting if some of our equi-tech, Torus, Audioquest Niagra, Shunyata, Entrec, Tripoint, etc., owners here played around with an EM100 and reported the results.
 

Gjo

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This is interesting, wil! So maybe high EMI noise such as that detected by the EM100 doesn't translate into untoward and problematic sonic effects on the sound coming out of our stereos? Is worrying about high EMI readings just audiophile nervosa?

On the other hand it seems to me that a high ambient EMI environment couldn't be doing anything good for the sound coming out of our stereos . . .

It would be interesting if some of our equi-tech, Torus, Audioquest Niagra, Shunyata, Entrec, Tripoint, etc., owners here played around with an EM100 and reported the results.
Since you opened the door to discussion about the effect (or non-effect) of EMI reduction on a system's sound I will offer my observation. The only EMI filter that eliminated EMI as advertised by the manufacturer, OnFilter CleanSweep, had no sonic affect on my system's sound. The manufacturer made no claims that it would do so.

AC Filters I tested included: AudioQuest Niagara 1200 and 3000, PS Audio Stellar P3, Synergistic Research Powercell 12 UEF SE, Puritan Audio PM156, OnFilter CleanSweep. EMI was reduced in all cases, but with the exception of the OnFilter CleanSweep, EMI was never as low as manufacturers' claims.

I don't recall ever testing EMI from a filter that was higher than from the wall. However, it's been several years since I did the testing.
 
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microstrip

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I have posted before on the subject before, the influence of EMI/RFI in stereo systems is poorly understood and the bandwidth of EMI/RFI goes along many decades. IMHO we can't get any systematic or useful conclusion for audio using just a gadget to measure it. Unfortunately a decent RF spectrometer will cost a minimum of $5K.
 

Cellcbern

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In my system the addition of each of the following has produced audible incremental reductions in noise revealing more of the music:
-Bybee Stealth Power
-
I have posted before on the subject before, the influence of EMI/RFI in stereo systems is poorly understood and the bandwidth of EMI/RFI goes along many decades. IMHO we can't get any systematic or useful conclusion for audio using just a gadget to measure it. Unfortunately a decent RF spectrometer will cost a minimum of $5K.
It doesn't have to be understood or measured if it can be heard and reduced/eliminated.
 

Folsom

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This is interesting, wil! So maybe high EMI noise such as that detected by the EM100 doesn't translate into untoward and problematic sonic effects on the sound coming out of our stereos? Is worrying about high EMI readings just audiophile nervosa?

On the other hand it seems to me that a high ambient EMI environment couldn't be doing anything good for the sound coming out of our stereos . . .

It would be interesting if some of our equi-tech, Torus, Audioquest Niagra, Shunyata, Entrec, Tripoint, etc., owners here played around with an EM100 and reported the results.

Well the noise isn't always equal in what it's doing. For example a little noise from a regenerator may not cause any ringing effects, but some on the line might "color" your sound a lot because your transformer gets saturated. Also not everything is from the wall... there's also a potential for common mode noise between equipment.

If you can't tell by now I'm pretty much saying your little meter is only a minor indicator that tells you VERY LITTLE. This isn't speculation. We have been working on power conditioning concerns for many years now.
 

Alrainbow

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I don’t want to push bull but what does this tester test ? EMI is not noise on the lines I think. it’s the effect of it on the lines
the result is not noise per say
RFI is more noise on lines
as is many types of noise
voltage variation
dc noise on lines
total imp on lines
excuse my spelling on this next line
shunyata makes a denali
its a Simple noise filter
a tank circuit tuned to have a low resistance high reactive to higher freq noise on lines
can be seen on oscope uSed above the signwave
if you used the tester above on the same outlet it’s plugged into its low as low as output of the filter
why is simple the filter goes in both directions just like AC power does
now as I don’t know what this above tester is testing on
it can be the noise of the regen
no matter what any regen does it’s not a perfect sign wave under load or not
power is generated by opposing magnetic poles
not ossolation
like a regen does. As such it has to be controlled or regulated
this means it has a reaction time.
now our own power is also effected by varying loads too.
how any noise is effecting a PSU is in design not just n on lines of any type
 

adyc

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I have posted before on the subject before, the influence of EMI/RFI in stereo systems is poorly understood and the bandwidth of EMI/RFI goes along many decades. IMHO we can't get any systematic or useful conclusion for audio using just a gadget to measure it. Unfortunately a decent RF spectrometer will cost a minimum of $5K.
$5k is not expensive in audio world. The problem is whether audiophiles do know how to use this or more importantly how to interpret the results.
 

adyc

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Well the noise isn't always equal in what it's doing. For example a little noise from a regenerator may not cause any ringing effects, but some on the line might "color" your sound a lot because your transformer gets saturated. Also not everything is from the wall... there's also a potential for common mode noise between equipment.

If you can't tell by now I'm pretty much saying your little meter is only a minor indicator that tells you VERY LITTLE. This isn't speculation. We have been working on power conditioning concerns for many years now.
This meter is useful to tell whether turning on electrical appliances in the house have any effects on the electrical circuit of my Hi-Fi room.
 

Ron Resnick

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I, too, am not sure what the EM100 is actually measuring. Other than having an easy to read digital display, I am not convinced it's measuring anything more than my portable AM radio with a telescoping antenna set up amateur radio-style for EMI sleuthing.

The open question to me is can we perceive subjectively any correlation between a higher EM100 reading and deleterious sonic effects from our stereos.
 
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Ron Resnick

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And you couldn't distinguish that with your ears?

I sure hope not! If turning on a light in my kitchen made my stereo sound noticeably less natural I'd say I have an audio component that is poorly designed!
 

Alrainbow

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I still own a ps audio P10
I use it in my nyc place just for front end
pre amp
phono pre
lps supplies for digital
it’s fed from a BIG TYPO correction ( 2.5 KW ) balanced iso transformer
220 volt in to cut down on dc noise on mains
120 volt output to above devices
the combo can be heard fairly obvious
an increase in lower level detail is my observation
if we lower noise in analog or digital the observation I can hear is better low level details.
Same we may hear with a better pre amp or phono pre
 
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Ron Resnick

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I still own a ps audio P10
I use it in my nyc place just for front end
pre amp
phono pre
lps supplies for digital
it’s fed from a 10k balanced iso transformer
220 volt in to cut down on dc noise on mains
120 volt output to above devices
the combo can be heard fairly obvious
an increase in lower level detail is my observation
if we lower noise in analog or digital the observation I can hear is better low level details.
Same we may hear with a better pre amp or phono pre

Hi Al,

Why did you choose a regenerator over an isolation transformer (or balanced power + isolation transformer)?
 

Folsom

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The open question to me is can we perceive subjectively any correlation between a higher EM100 reading and deleterious sonic effects from our stereos.

It's not enough information to be definitive all the time. If the levels are REALLY high, well then it would be likely.
 

Ron Resnick

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It's not enough information to be definitive all the time. If the levels are REALLY high, well then it would be likely.
What EM100 noise level do you think would constitute "really high"?
 

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