The Final Chapter Kill EMI

[DeadTrader]

Well I finally have reached the point that I'm very happy with every piece of equipment in my system. The last little bit was some tube rolling in the DAC, to get that synergy between it and a new network transport.

So what's left EMI? It does exist, and it's measurable. Does it matter? I guess there's no way to know unless you remove it.

Power conditioners, This Could be the least data-driven category in all of audio. No real compatible data, Just lipstick and perfume. So I changed my search to " Scientific equipment EMI filter". What I found was a collection of filters with specs.

This one looked like a good candidate. Any thoughts?

AC Power Line EMI Filters | OnFILTER

Plug-and-play CleanSweep AC Power Line EMI filters reduce electromagnetic interference where it matters - in your application. CleanSweep EMI filters offer superior EMI attenuation than regular filters, providing noise reduction in both differential and common modes, and, uniquely, in ground.

www.onfilter.com

 

[avionic]

So what's left EMI? It does exist, and it's measurable. Does it matter?

Depends on the Final Chapter.

 

[motorstereo]

I remember going on a similar quest once I had the electronics I wanted. Then the power went out and I fired up my "clean" dc converter generator. The amount of emi that generator produced was ridiculous compared to household electricity. If memory serves correct it was close to 2000 while household ac is around 300.

I noticed zero change in the sound on household vs generator so that ended that quest. I already had a Furman ref 20i pc, and several quiet lines and ps audio de-noisers which do reduce emi. Playing around a bit more I piggy backed my belkin pc onto the furman which reduced my emi into the single digit area. Again there was no change in the sound to my ears. I could see the emi getting reduced on my emi meter but no change soundwise.

 

[DeadTrader]

I remember going on a similar quest once I had the electronics I wanted. Then the power went out and I fired up my "clean" dc converter generator. The amount of emi that generator produced was ridiculous compared to household electricity. If memory serves correct it was close to 2000 while household ac is around 300.

I noticed zero change in the sound on household vs generator so that ended that quest. I already had a Furman ref 20i pc, and several quiet lines and ps audio de-noisers which do reduce emi. Playing around a bit more I piggy backed my belkin pc onto the furman which reduced my emi into the single digit area. Again there was no change in the sound to my ears. I could see the emi getting reduced on my emi meter but no change soundwise.

That's what I was wondering about. Would I be able to hear a difference if EMI was drastically reduced. There has to be something to it. All modern equipment with switching power supplies (EMI generator) have a large bank of capacitors to smooth out the power and in doing so, reduce the EMI

 

[motorstereo]

That's what I was wondering about. Would I be able to hear a difference if EMI was drastically reduced. There has to be something to it. All modern equipment with switching power supplies (EMI generator) have a large bank of capacitors to smooth out the power and in doing so, reduce the EMI

I wasn't able to hear a difference but that doesn't mean you won't be able to. And yes those switching wallwarts do add a great deal of emi to the line. In my case I had several 12 volt wallwarts for my lighting and they were causing problems with my digital playback. I replaced them with one large non switching unit which took care of the issue. Did I notice a change in the sound? No; but it did stop my digital playback from being interrupted every few minutes.

 

[RVT1K]

I wasn't able to hear a difference but that doesn't mean you won't be able to. And yes those switching wallwarts do add a great deal of emi to the line. In my case I had several 12 volt wallwarts for my lighting and they were causing problems with my digital playback. I replaced them with one large non switching unit which took care of the issue. Did I notice a change in the sound? No; but it did stop my digital playback from being interrupted every few minutes.

I wasn't having an issue with noise but I got rid of five wall-wart/USB power supplies and replaced them with two linear power supplies. I have a 12VDC unit that is now powering my DSP-408 and two AC Infinity fans. I also have a 5VDC unit that is now powering my Topping E50 II and Schitt MODI 3.

I can't say that I can hear any difference but it did neaten things up a bit.

 

[doctor fuse]

Looks like typical Audiophile Poo Poo dressed up in 'legitimate' tech disguise. Amiright?

 

[PE9ZZ]

If memory serves correct it was close to 2000 while household ac is around 300.

"300" what? Without units numbers have no meaning. EMI affects radio reception. Just hold any AM portable next to a switchmode wall wart or whatever power supply. Reception becomes impossible.

EMI usually is in V/m, I can hardly believe your levels are that high.

 

[PE9ZZ]

That's what I was wondering about. Would I be able to hear a difference if EMI was drastically reduced. There has to be something to it. All modern equipment with switching power supplies (EMI generator) have a large bank of capacitors to smooth out the power and in doing so, reduce the EMI

These capacitors only store energy. The filtering takes place in inductors (combined with other capacitors). EMI manifests itself as radio waves. Humans cannot detect those. EMI can have an influence in amplifiers. Just hold your cellfone next to an amp. The sound it then makes is notorious for badly filtered amplifier inputs.

 

[motorstereo]

"300" what? Without units numbers have no meaning. EMI affects radio reception. Just hold any AM portable next to a switchmode wall wart or whatever power supply. Reception becomes impossible.

EMI usually is in V/m, I can hardly believe your levels are that high.

They're units of measure given on my emi meter and to me they serve as a reference point. See there; now while I couldn't hear a difference in sound on my rig while reducing emi from well over 1,000 to single digits it appears that you just may be able to while listening to your portable am radio next to a wallwart.

 

[PE9ZZ]

They're units of measure given on my emi meter and to me they serve as a reference point.

But surely those numbers have a unit? Otherwise you can only reference to your own meter and nothing else. It's like that crash-landed Mars module many years ago. It crashed because someone mixed imperial and metric units.

 

[stoutblock]

Only electrical interference I’ve had to deal with is to make sure I keep my WiFi router at least 4’ away from any mag tape deck or the heads pick up some major noise during playback.

 

[motorstereo]

But surely those numbers have a unit? Otherwise you can only reference to your own meter and nothing else. It's like that crash-landed Mars module many years ago. It crashed because someone mixed imperial and metric units.

Here you go along with this morning's household reading in the 300 range. I'm not dragging out my generator so you'll have to take my word for it that's it's loaded with emi. You'll also have to take my word for it that I'm unable to distinguish between gen power and household on my main rig. Just as I'll take your word for it that wall warts cause issues with your portable am radio.

 

[RVT1K]

These capacitors only store energy.

They can also provide a low impedance path to ground for high frequencies.

 

[PE9ZZ]

They can also provide a low impedance path to ground for high frequencies.

They have to otherwise you get losses. Heat. You don't want that. Those are the reservoir capacitors. The EMC capacitors are in a seperate part of the PSU. Sometimes they are not installed. EMI-wise that is bad.

@motorstereo: Will look up your tester. It sez "mV" but there are many sorts of millivolts. And how it manifests itself.

The AM portable test you can do yourself. Unless you have no radios of course.

Edit: looked up the manual (below) and your value is actually in mVpp. That is unusual, I'd expect an RMS value. Maybe that was easier for them to indicate. And all the noise is measured above 10 kHz so none of it you can actually hear. I don't believe it complies with any EMC standard. The manual is mum about those.

 

[Bill Ferris]

Here you go along with this morning's household reading in the 300 range. I'm not dragging out my generator so you'll have to take my word for it that's it's loaded with emi. You'll also have to take my word for it that I'm unable to distinguish between gen power and household on my main rig. Just as I'll take your word for it that wall warts cause issues with your portable am radio.
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FWIW, I also own that EMI meter that I bought around 5 yrs. ago.
And its use has confirmed my inherent concern about various back feeding pollution into my powerline creating noise generation devices, which aside from all SMPS` also including LED light bulbs when operating, as well as common lighting dimmers if used.
Plus my 2 neighbors who share my drop transformer contribution to my own inhouse created power line pollution.

I personally wasn`t concerned with it (the EMI tester ^^) displaying absolute figures, just providing numerical figures of reference merit to compare between the insertion of different brand power line type filters/conditioners, and initially comparing to no noise filtering at all (the lower the displayed reading the better), and its use provided me with the information I was looking for, as I had already been purchasing and using for multiple decades various brand & performance capabilities of surge/spike/power conditioners, & later (after 1999) AVRs which included the protection and power line filtering, being living in hurricane magnet/lightning alley NE. FL. and having a whole house capable (25 kw) auto standby generator and wishing to protect my house`s multiple room A/V systems from any generator created noise, surges/spikes that might be created when inductive heavy electrical load devices switched on/off like my 3.5 ton Heat pump, fridge, yard irrigation pump, etc. while using any of my stereos, or A/V systems during a sustained grid failure.

I`m quite happy with its purchase & use and the effectiveness of my chosen power line conditioners.

 

[motorstereo]

Edit: looked up the manual (below) and your value is actually in mVpp. That is unusual, I'd expect an RMS value. Maybe that was easier for them to indicate. And all the noise is measured above 10 kHz so none of it you can actually hear. I don't believe it complies with any EMC standard. The manual is mum about those.

This doesn't matter to me in the least. As I mentioned already I'm using those numbers as a reference point for comparison sake. Read Bill Ferris's post for a more detailed explanation of how that works.

 

[theophile]

EMI would like to know why the angst?

 

[DeadTrader]

I just ordered an EMI meter, just to see what's going on around the house. Then I might jump into killing this criminal.

And @theophile I'm really sorry to have EMI Records being brought into the fray, I'm sure there is no collusion going on here.

 

[PE9ZZ]

Fortunately it's about EMC, or electromagnetic compatibility. EMI is the measurement. Or the record company (which is not compatible).