I also have an older Furman PST-8 that I’ll test when I get a meter. This is cool! We can compile results in some sort of power source guide. 
Edit:
We need some PP owners. I think @Rhodey is down to try it. He has a PP3. 
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I think I have decent power from the wall too. Should be interesting.
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Ill also send to @DanMellinger and @sa11297 to test their niagara and pp
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I’ve been wanting to get a meter for a while and maybe this will finally push me over the edge. I bought one of these a few months ago and have been happy with it so far:
Just a giant isolation transformer. I keep meaning to order some outlets for it. The power cord it’s plugged into the wall with probably cost more in parts than the unit itself 
I will make a decision on PP vs Audience vs PSM156 some day soon.
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That’s cool. Decware makes something similar. I’ve toyed with the idea of feeding a pair of Power Stations with one.
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I think that uses the same balanced conditioning technology as my Core Power Equi Core, doesn’t it?
@Draaly maybe send it over with the rest of the gear… I’ll test it with my PP3
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Here are the readings in my system. Noise from the wall is very low so power conditioner isn’t doing a ton. But the tone of the noise from the Puritan PSM156 is much smoother sounding then from the wall. I’m not sure what the sound coming from the EMI meter indicates but it’s not as annoying when it’s connected to the conditioner.
Power from the wall (direct line 15A):
Power from conditioner with everything on (MC1, Serene, First Watt):
The First Watt raises the reading on the EMI meter quite a bit. The Tyrs raise it a little but not to the same extent. And the source components don’t have much of an effect on the mV reading from the meter. I know most people don’t connect power amps to conditioners but I haven’t noticed any negatives from doing it like this. Especially since the power limit of the Puritan is so high.
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Retested this morning with iFi PowerStation, connected to the wall via iFi supanova cable. I’m down to 35mV:
Highest I’ve seen from the wall is around 230mV, depending on what else is turned on in the house.
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So this little dookie is only measuring emi from the wall? What about other sources of interference which could be measured, are there other more thorough tools?
It’s a pretty limited tool, but it gives some indication of emi on a power line. It only covers 10kHz to 10MHz bandwidth, the accuracy over that bandwidth isn’t consistent (lower at higher frequency). And I’m not exactly sure how the pk-pk noise is measured: is it averaged over the bandwidth? The worst case over that bandwidth? In general I would say it’s a figure of merit that can be used to compare if changes you make are going in the right direction. It’s also helpful for finding noise sources in your house by turning things on and off. But it’s no guarantee of audio performance improvement.
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That right there is worth its dookie weight! I had a dc offset hum caused by under cabinet lights in my kitchen. I spent hours tracking it down until one day my girlfriend turned off those lights and I noticed the transformer hum was gone.
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Out of curiosity I added an extra iFi iSilencer to the power station:
This got me down to ~30mV from ~35mV before. So some measurements improvement.
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What if electricity when free of noise, was just like DACs that measure extremely well but… 
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I hate you so much
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It’s been cool seeing all these different results.
Also surprising to see a 5mV decrease by adding an additional iPurifier @elementze. Looking forward to further results.
Edit:
Nice cable management. 
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Had some fun measuring my power thanks to @elementze who sent me his meter.
Very interesting results. First off, my power is much cleaner than I thought it would be. I also had three different power solutions that I tested: iFi Power Station, Furman Power Conditioner PST-8, and a Belkin Power Strip Surge Protector.
I tested the outlets at various locations in my home and the results were very surprising. All pictured results are taken with all equipment connected and running at their respective locations which includes tube/SS amps, VU meters, usb chargers, lighting, etc. The iFi was the sole audio-only setup. All outlets for the power strips measured about the same (the differences were negligible).
iFi Power Sation, 42.7
Furman Power Conditioner PST-8, 57.9
Belkin Power Strip Surge Protector, 57.0
These are the measurements for the outlets. The three outlets measured virtually the same so I only took one photo since it’s a fair representation of the three locations.
29.2 with an average of 30
Lastly, this is the quietest measured location in my home which was the kitchen.
24.9 with an average of 25
My outlets are quieter than any power solution that I currently own with the iFI Power Station being the quietest of the three.
Another interesting observation was that the iFi iPurifiers injected noise into all sockets tested, Wall or Power Strip. On the iFi they added about 3mV each. With the Furman they added an average of 10mV each with similar but slightly lower averages on the Belkin.
The noisiest measurement recorded was the Furman with the 2 iPurifiers getting an average of 80mV.
I also tested with and without equipment connected, but the differences were also negligible. The three tested about the same with or without electronics connected.
Subjectively I find the iFi to sound the best to my ears, adding quieter backgrounds, and greater dynamics.
This was a really fun exercise, and I learned that my power is better than any solution that I currently own. Go figure. 
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I think there is something to this.
Although with the 2 iPurifiers plugged into the Power Sation there is more measurable noise (6mV worth), I actually think that it sounds better with them in place. The staging is more holographic, and images are more focused.
I also don’t hear an increase in noise floor, so that’s kind of interesting.
I measured this morning since most of my neighbors are still sleeping, and I got slightly lower numbers.
One other thing I did out of curiosity was to swap out the stock C7 cable on the meter with an Wireworld Mini Stratus. It measured more noise than the stock cable (averaging 5mV more noise).
I use that Wireworld on my Apple TV and I visually see less banding on the older Samsung LCD TV that it’s connected to just by using the Wireworld. I think it’s really interesting since it measures worse, but performs better to my eyes.
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I’ve been since told elsewhere there is something to this from certain vendors saying just that.
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It’s probably like THD, a number can’t sum up the composition of the noise, and that could dramatically affect what we perceive. Most of these filters and that meter concentrate on higher frequency noise, but I suspect that’s the stuff most PSU’s are good at removing anyway, and I’ve never seen an analysis of what noise on the power line is actually important.
In the Amp space for example -40dB/1% THD is terrible if it’s all odd harmonics (say most SS amps), but if it’s mostly 2nd harmonic, it might sound very good, ask anyone running speakers with low wattage DHT amps.
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