[jeffreybehr]

I bought a 'Green Wave Broadband EMI Meter' thru Amazon...
https://www.amazon.com/gp/product/B01MEFVYQD/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
...just for kicks and measured a few outlets in my musicroom.  A nondedicated outlet on the back wall measured 200 - 300 mV, while the lowest measurement came from an unused outlet of my Balanced Power Technologies 3.5 Ultra at around 50mV.(1)

One thing I've been wondering about is just how much the sounds from a device that's fed in parallel from one duplex outlet is altered by the noise created by its 'partner'.. I measured the noise from an outlet in a general- purpose branch circuit that feeds my projector.. It measured around 200mV with the projector plugged in but not turned on; with the PJ turned on, it measured over 2000mV!!!!!!!!!!  (I did NOT measure, in the same way, noise from outlets of the BPT3.5.).. I wonder how such noise affects the sounds of other equipment.. I have to think that audience's method of filtering and isolating EACH outlet of, for instance, the 12 in an aR-12 conditioner...
https://www.audiocircle.com/index.php?topic=106120.msg1134610#msg1134610
...both inductively and capacitively does a much better job of NOT feeding noise created by a piece of equipment into its partner outlet.. Such groupings or partnerships can be large.. For instance, my BTP has all-12 outlets fed in parallel.. While each duplex outlet has a small EMI-filtering cap on it, that looks to me like a rather feeble effort at isolation.. PS Audio's P20...
https://www.psaudio.com/directstream-p20-power-plant/
...has five groups of 2 or 3 duplex outlets.. Each outlet within each group is driven in parallel with NO isolation among the other outlet(s) of that group.. I'm wondering how that can be good!

What do we think about this?


(1) Before I get flamed too hotly, allow me to state that I believe, first, that EVERY change to a music-reproduction system changes its sounds, whether you or I or the next guy can hear those changes--or not; that such subtle changes are cumulative; and it's not what's measured but what's (very carefully) heard that matters..  After all, "...not everything that can be counted counts, and not everything that counts can be counted."  (William Bruce Cameron)

(2) I also believe that most of us use way-too-'large' superlatives to describe changes in sound quality.  Such terms include 'night and day', 'black and white', and my unfavorite, 'totally different'.. Perhaps the 'biggest' my perception gets is 'clearly audible'.

(3) I think my thinking about this entire subject is a result of a flare-up of my GAS, in that my current system...
...is the best-sounding system I've EVER heard(4)  and is definitely an improvement over that from, say, a year ago.. I think most of those improvements are due to the addition of both a pair of Quad '2905s and Atma-Sphere MA-1 poweramps and my minor improvements to the latter.

(4) Do understand that I don't go about searching for SOTA music-reproduction systems.   

[Elizabeth]

Here in a link to my experience with AC duplex noise: https://www.audiocircle.com/index.php?topic=162162.0

[audioengr]

I am not a fan of putting inductance between power grounds in a conditioner or inductance and capacitance used as AC line filtering.  This can easily cause the system to slow in response, by impacting di/dt.  In fact, I'm no fan of conditioners.  I use a Plasmatron for digital power, but it's a regulator, not a conditioner.  I did have one AC adapter that caused noise in an amplifier I used at a show once, but that was the only time I had a problem.  AC power in hotels is notoriously bad.

If you have one or more ground-loops, which most do, the inductance can cause intermittency and sound quality problems.  The best way to deal with safety grounds is to use one on every component and then find ways to break the ground connection between every component.  I have done this in my system and it's dead-quiet.  You can isolate both digital and analog using various methods.

Steve N.
Empirical Audio

[Speedskater]

Surprise! once again I agree with Steve.

It is best to reduce the impedance from chassis to chassis of all your hi-fi components.  This means short heavy Safety Ground wires in your cords all connected to the same place.

Nothing good can come from putting inductors in the Safety Ground runs.

[jeffreybehr]

Steve and Speed, who said anything about putting inductors in ground lines?  Audience winds each pair of common and hot leads thru an inductor, but green-ground/earth is always anchored solidly to earth.. Or am I missing something here?

[audioengr]

Steve and Speed, who said anything about putting inductors in ground lines?  Audience winds each pair of common and hot leads thru an inductor, but green-ground/earth is always anchored solidly to earth.. Or am I missing something here?

As I said, inductance between the grounds OR inductance in the line feeds is bad.

Steve N.

[Speedskater]

Steve and Speed, who said anything about putting inductors in ground lines?  Audience winds each pair of common and hot leads thru an inductor, but green-ground/earth is always anchored solidly to earth.. Or am I missing something here?

It's doubtful that it's connected solidly to Planet Earth even at DC and power line frequencies.  Making a good connection to Earth is not easy or inexpensive!
But putting a choke (or even a wire with several loops) makes the high frequency impedance to Earth sky rocket.
And adding in the choke impedance slows down the circuit breaker time.

[Wayner]

I bought a 'Green Wave Broadband EMI Meter' thru Amazon...
https://www.amazon.com/gp/product/B01MEFVYQD/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
...just for kicks and measured a few outlets in my musicroom.  A nondedicated outlet on the back wall measured 200 - 300 mV, while the lowest measurement came from an unused outlet of my Balanced Power Technologies 3.5 Ultra at around 50mV.(1)

One thing I've been wondering about is just how much the sounds from a device that's fed in parallel from one duplex outlet is altered by the noise created by its 'partner'.. I measured the noise from an outlet in a general- purpose branch circuit that feeds my projector.. It measured around 200mV with the projector plugged in but not turned on; with the PJ turned on, it measured over 2000mV!!!!!!!!!!  (I did NOT measure, in the same way, noise from outlets of the BPT3.5.).. I wonder how such noise affects the sounds of other equipment.. I have to think that audience's method of filtering and isolating EACH outlet of, for instance, the 12 in an aR-12 conditioner...
https://www.audiocircle.com/index.php?topic=106120.msg1134610#msg1134610
...both inductively and capacitively does a much better job of NOT feeding noise created by a piece of equipment into its partner outlet.. Such groupings or partnerships can be large.. For instance, my BTP has all-12 outlets fed in parallel.. While each duplex outlet has a small EMI-filtering cap on it, that looks to me like a rather feeble effort at isolation.. PS Audio's P20...
https://www.psaudio.com/directstream-p20-power-plant/
...has five groups of 2 or 3 duplex outlets.. Each outlet within each group is driven in parallel with NO isolation among the other outlet(s) of that group.. I'm wondering how that can be good!

What do we think about this?


(1) Before I get flamed too hotly, allow me to state that I believe, first, that EVERY change to a music-reproduction system changes its sounds, whether you or I or the next guy can hear those changes--or not; that such subtle changes are cumulative; and it's not what's measured but what's (very carefully) heard that matters..  After all, "...not everything that can be counted counts, and not everything that counts can be counted."  (William Bruce Cameron)

(2) I also believe that most of us use way-too-'large' superlatives to describe changes in sound quality.  Such terms include 'night and day', 'black and white', and my unfavorite, 'totally different'.. Perhaps the 'biggest' my perception gets is 'clearly audible'.

(3) I think my thinking about this entire subject is a result of a flare-up of my GAS, in that my current system...
...is the best-sounding system I've EVER heard(4)  and is definitely an improvement over that from, say, a year ago.. I think most of those improvements are due to the addition of both a pair of Quad '2905s and Atma-Sphere MA-1 poweramps and my minor imporvements to the latter.

(4) Do understand that I don't go about searching for SOTA music-reproduction systems.   

I have found that the problem is actually caused by induction from each components transformer. Tripp-lite offers isolated outlets for just this reason. A worse case is using multiple outlets that are on different branch circuits for one system. That really screws up the sound stage.

[audioengr]

Agreed.  Never use two circuits that are off different phases in one audio system.  Guaranteed hum and ground-loop noise.

Steve N.

[Elizabeth]

I do not now if this info applies.. but I will mention it anyway..
When I was checking all my AC duplex wit ha borrowed noise sniffer.. It was interesting that many devices added (out of 000 to 999 range of the sniffer) like 30 or so to the noise. A few removed some of the noise in the AC line when turned on! And the worst offenders, the CD changers added 700 or so, each, to the AC lines. The other big offender was the Plasma TV when turned on. (When it was off, zero added. so I did not worry about it, since it is off when listening to music.)
I already have the two CD players on a separate conditioner, isolated form the other stereo gear.
And finally stuff like light dimmers, even though on different circuits, added noise to all lines in the apartment. The noise found it easy to spread all around..

[Speedskater]

The noise sniffer is a toy.  Just return it to it's owner.

[Elizabeth]

The noise sniffer is a toy.  Just return it to it's owner.

A useful toy. I noticed it on my local Magnepan dealers site in conjunction with Isotek AC gear.
He let me borrow it over a weekend. It was returned a long time ago.
It was 'fun' to 'play' with, as a toy should be. It allowed me to see what equipment was putting a lot of hash into the AC lines. and which was actually removing the stuff.
So I call it useful fun. Free useful fun.
I actually had noticed some of the kind of info from a few PS Audio Noise Harvesters I bought. They just blink when they are 'destroying' the noise (though in conjunction with the borrowed noise sniffer, I realized the PS Audio units where removing noise from the line even when not blinking.) The noise sniffer helped my to best place the seven PS Audio units I bought when on sale for $50 a pop.
I enjoy your denigrating attitude btw. If I wanted to buy and use an oscilloscope to find 'better qulity info about my AC I would have. the noise sniffer was the best sort of free. My dealer allowed my to borrow it, no problem, he felt good loaning it, I liked it. no problem, 'cept maybe yours? LOL

The little PS Audio Noise Harvesters on the main audio lines are usually silent (not blinking) until I turn on the bedroom dimmer halfway... Then both lines with two each of the Noise Sniffers start to blink in the living room.. Just sayin'.

[Speedskater]

Not at all useful!

a] It measures RFI voltage in the air (not leakage, noise and interference currents in the wires).
b] It does not quantify what it measures ( is it 100kHz or 100MHz).
c] It is not other user reproducible (another user who did not see the first use make his measurements may return very different values).
d] The user can reposition the probe until they get the reading that they want.
e] RFI should be dealt with at it's source or at the chassis of the affected hi-fi component (not at a wall outlet box).

[Elizabeth]

Can you explain how 'it measures RFi voltage in the air" when it only registers WHEN IT IS PLUGGED INTO THE AC duplex?
True it does not register the specific frequency of the noise. (it is designed for idiots to use. true.)
Sorry the device is user reproducible. repeated use gives the same values (with the same variables).
Reposition the probe? Yes it is either in the AC duplex or not. LOL
And the final complaint is a hell of a lot of work, perhaps you should stat a business fixing the millions, perhaps billions of electrical object that fail your level of perfection.
added. my only guess is you are thinking of a "voltage detector" which is a different sort of device and is used to detect voltage RFI 'IN THE AIR".. I own one of those, a Greenlee GT-16, they cost $23 on Amazon, and not the $2000 the device I borrowed cost.

[jeffreybehr]

Can you explain how 'it measures RFi voltage in the air" when it only registers WHEN IT IS PLUGGED INTO THE AC duplex?
True it does not register the specific frequency of the noise. (it is designed for idiots to use. true.)
Sorry the device is user reproducible. repeated use gives the same values (with the same variables).
Reposition the probe? Yes it is either in the AC duplex or not. LOL
And the final complaint is a hell of a lot of work, perhaps you should stat a business fixing the millions, perhaps billions of electrical object that fail your level of perfection.
added. my only guess is you are thinking of a "voltage detector" which is a different sort of device and is used to detect voltage RFI 'IN THE AIR".. I own one of those, a Greenlee GT-16, they cost $23 on Amazon, and not the $2000 the device I borrowed cost.

Elizabeth, FWIW, I agree with your view of the device you used.. Mine's about the same.. IMO the LEAST it'll do for an audio/video system is to identify the individual components--such as my projector--that generate more noise than others so that we can try to reduce that noise introduced into the system.

------------------------------------------------

On another subject, I have arranged with AudioQuest* to borrow a Niagara 7000 power conditioner for a couple months in a couple months.. I'm pretty happy with my BPT Ultra-3.5 Imp., but it never hurts to know which is better or even if I can hear a difference.. Fortunately, I substantially rebuilt and reconfigured my equipment stand recently...

...and both conditioners use 20-amp power inlets, so switching back and forth will be fairly easy.

* I was an AQ dealer for a few years in the 1980s, and we're still 'friends'.

[Speedskater]

Oops!  I had it confused with another test instrument.
I thought is was a budget version of the 'Tri-Field' meter.
* * * * * * * * *
so then, you could use it to determine which of your hi-fi components s generating the noise.

[Elizabeth]

OK no harm done. 

[OzarkTom]

I have found that some amplifiers sound best plugged straight into the wall. I always try both ways.

[Elizabeth]

I have gone back and forth from plugging amplifier into conditioner, then back to wall many times.
The conditioner gives a little more carity, the wall less clarity but more fullness.
Right now from the wall. And it seems that is where it is staying..

[jeffreybehr]

...any capacitance across hot and neutral...
PS Audio: "...Similar plug-in noise reduction devices simply place a capacitor across the AC line which only shunts line noise from hot to neutral but does not eliminate it.  Only a Noise Harvester collects and stores the noise in a capacitor and when enough energy is available, discharges all the unwanted noise into light and it’s gone forever."
...plugging one into the same outlet as high-noise-producing equipment (such as my projector) might elimate at least SOME of the EMI before it corrupts that branch circuit and then all branch circuits connected to that leg.. I used them years ago but before my system and my ears became as resolving as they are now, so I have no applicable experience with them.

I have seven* coming, so we'll see.

Anyone have an opinion?

* I made an offer on two used ones before I bought a new 5-pack from PSA.. My wonderful wife calls me Mr. Excess for good reason..