Want to point out that series mode power conditioners are essentially low pass filters that start working ~ 3 kHz. True for ZeroSurge and Furman with SMP while AFAIK, RFI filters usually start in the 10s of kilohertz. This is why I always recommend them for noise filtering efficiency.
Parallel filtration has a difficult time filtering out lower than that due to the limitations on caps across the hot and neutral. YMMV.
Also, keep your dirty power supplies (computer, cheap wall warts) out of the clean side of a power conditioner and use shielded power cables to ensure you don't suffer re-infection of noise after the power has been cleaned up.
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Actually, I study the owners manuals online of products I am considering purchasing. My brother says the owners manual/assembly instructions are just one engineer’s opinion. My brother breaks things a lot.
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Otherwise if they publish the data then people can easily point out the issues with their asking price and actual performance.
@audio_phool you answered your own question. While data might be useful to customers, it will not be beneficial to the manufacturers unless they have top/best measurements. In fact, it’ll create more work (accumulating data, publishing data, answering data related questions) and likely loss of sales/revenue to do so. Also, many claim to “lower noise”, but it may not be exactly/simply the same as specifically “EMF/RFI” like you are interpreting
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@tonywinga Thank you for pointing out the user manual part. Now I have created a table of values for EMI/RFI Noise reduction based on available/published spec. Took me some time to gather all info. But I think its a worthwhile exercise.
Sr. No. |
Manufacturer |
Model |
EMI/Noise Reduction |
Mode Specified |
Load Specified |
Cost |
1 |
Shunyata |
Everest |
More than 50dB, 68db @ 1 Mhz |
No |
No |
USD 9,900 |
2 |
Shunyata |
Gemini |
More than 40dB, 28dB @ 1 Mhz |
No |
No |
USD 1,998 |
3 |
Shunyata |
Venom PS10 |
More than 24dB, 28dB @ 1 Mhz |
No |
No |
USD 900 |
4 |
Audioquest |
Niagra 5000 |
More than 30db for CM & ore than 28 dB for DM |
Yes, CM & DM |
10 to 50 ohms |
USD 5,900 |
5 |
Audioquest |
Niagra 7000 |
More than 30db for CM & ore than 28 dB for DM |
Yes, CM & DM |
10 to 50 ohms |
USD 11,000 |
6 |
Audioquest |
PowerQuest 303 |
More than 22 dB for DM |
Yes, DM |
10 to 50 ohms |
USD 460 |
7 |
Synergistic Research |
Galileo PowerCell SX |
No |
No |
No |
USD 27,995 |
8 |
Synergistic Research |
PowerCell SX |
No |
No |
No |
USD 9,000 |
9 |
Synergistic Research |
PowerCell ONE |
No |
No |
No |
USD 1,095 |
10 |
PS Audio |
Power Plant 20 |
More than 80 dB |
No |
No |
USD 8,000 |
11 |
PS Audio |
Power Plant 15 |
More than 80 dB |
No |
No |
USD 6,399 |
12 |
PS Audio |
Stellar Power Plant 3 |
No |
No |
No |
USD 2,399 |
13 |
IsoTek |
EVO3 Super Titan |
85dB, No mention of frequency range |
No |
No |
USD 12,495 |
14 |
IsoTek |
V5 Titan |
85dB, No mention of frequency range |
No |
50 ohms |
USD 4,995 |
15 |
IsoTek |
V5 Elektra |
55dB, No mention of frequency range |
No |
No |
USD 1,695 |
16 |
Puritan Audio |
PSM 156 |
No |
No |
No |
USD 2,400 |
17 |
Puritan Audio |
PSM 136 |
No |
No |
No |
USD 2,100 |
18 |
OnFilter |
AF Series |
Graph Provided for CM & DM. Max 98dB in DM, Max 62db in CM |
Yes, CM & DM |
1:100 |
USD 650 |
19 |
Schaffner |
FN 2090 20A |
Graph Provided for CM & DM. Max 100dB in DM, Max 82db in CM |
Yes, CM & DM |
50:50 |
USD 70 |
For any Power conditioner/Filter, it’s primary function is to reduce EMI/RFI noise on the mains line. Hence it’s objective performance is of high importance here. Now the performance of this noise filtering is evaluated based on the following parameters.
1. Noise reductionvalue:- The EMI Reduction value is expressed in the units of dB. Higher the value, better is the attenuation performance. Sometimes it’s also expressed as -ve dB value in that case lower the number better is the attenuation performance.
2. Frequency Range :- The performance of filter is not linear or constant over frequency range hence usually the graph of attenuation is plotted for range of frequency (Just like frequency response of speakers). For normal house hold scenario where noise is generated because of SMPS in LEDs, TV, fridges, washing machines etc, it’s frequency range usually lies around 100-150 KHz hence performance of any filter in this frequency range is crucial.
3. Mode :- EMI/RFI noise attenuation is measured in two modes Differntial Mode (DM) which is measured between live (hot) and neutral (cold) line (differential currents flow in opposite directions through the source and return path) and Common Mode (CM) which is about noise that flows in the same direction in a pair of lines (common mode currents flow in the same direction through the source and return path, completing the circuit through the ground path). Typically DM noise reduction values will be higher than CM mode values at a given frequency value & at the same load value. In both cases having higher values is desirable.
4. Load Values :- Typical Lab setting measurements are done with 50 ohms load and 50 ohms output impedance of power supply. These values often time look good (Schaffner publishes these lab values). But real world load and powerline impedances are anything but 50 ohms. Hence the realworld scenario would look like 0.1/100 where 0.1 ohm is the output impedance of powerline and 100 ohm is the load value or vice a versa 100/0.1. Schaffner removed the realworld performance data from their data sheets because it’s performance was worse in the area where it mattered the most viz. in 100Khz region.
Hence from above four points one can see what all needs to be looked at when looking for noise attenuation performance of any filter. So if any manufacturer specifies just a random number like PS audio for example, it doesn’t make any sense from the actual performance standpoint. Instead start asking for the hard facts based on these thingsfor the amount of money that we pay for these products.
@kennyc Yeah, now that you have pointed out, I can see that I had already answerd my own question. The table above puts hard facts around it.
Audio_phool
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I am adding a separate column for frequency range specified/mentioned.
Sr. No. |
Manufacturer |
Model |
EMI/Noise Reduction |
Frequency Range Specified |
Mode Specified |
Load Specified |
Cost |
1 |
Shunyata |
Everest |
More than 50dB, 68db @ 1 Mhz |
100 KHz to 30 Mhz |
No |
No |
USD 9,900 |
2 |
Shunyata |
Gemini |
More than 40dB, 28dB @ 1 Mhz |
100 KHz to 30 Mhz |
No |
No |
USD 1,998 |
3 |
Shunyata |
Venom PS10 |
More than 24dB, 28dB @ 1 Mhz |
100 KHz to 30 Mhz |
No |
No |
USD 900 |
4 |
Audioquest |
Niagra 5000 |
More than 30db for CM & more than 28 dB for DM |
3 Khz to 1 Ghz for DM & 60 Hz to 100Mhz for CM |
Yes, CM & DM |
10 to 50 ohms |
USD 5,900 |
5 |
Audioquest |
Niagra 7000 |
More than 30db for CM & more than 28 dB for DM |
3 Khz to 1 Ghz for DM & 60 Hz to 100Mhz for CM |
Yes, CM & DM |
10 to 50 ohms |
USD 11,000 |
6 |
Audioquest |
PowerQuest 303 |
More than 22 dB for DM |
3 Khz to 1 Ghz for DM |
Yes, DM |
10 to 50 ohms |
USD 460 |
7 |
Synergistic Research |
Galileo PowerCell SX |
No |
No |
No |
No |
USD 27,995 |
8 |
Synergistic Research |
PowerCell SX |
No |
No |
No |
No |
USD 9,000 |
9 |
Synergistic Research |
PowerCell ONE |
No |
No |
No |
No |
USD 1,095 |
10 |
PS Audio |
Power Plant 20 |
More than 80 dB |
100 KHz to 2 MHz |
No |
No |
USD 8,000 |
11 |
PS Audio |
Power Plant 15 |
More than 80 dB |
100 KHz to 2 MHz |
No |
No |
USD 6,399 |
12 |
PS Audio |
Stellar Power Plant 3 |
No |
No |
No |
No |
USD 2,399 |
13 |
IsoTek |
EVO3 Super Titan |
85dB |
No |
No |
No |
USD 12,495 |
14 |
IsoTek |
V5 Titan |
85dB |
No |
No |
50 ohms |
USD 4,995 |
15 |
IsoTek |
V5 Elektra |
55dB |
No |
No |
No |
USD 1,695 |
16 |
Puritan Audio |
PSM 156 |
No |
No |
No |
No |
USD 2,400 |
17 |
Puritan Audio |
PSM 136 |
No |
No |
No |
No |
USD 2,100 |
18 |
OnFilter |
AF Series |
Graph Provided for CM & DM. Max 98dB in DM, Max 62db in CM |
10 KHz to 50 MHz |
Yes, CM & DM |
1:100 |
USD 650 |
19 |
Schaffner |
FN 2090 20A |
Graph Provided for CM & DM. Max 100dB in DM, Max 82db in CM |
10 KHz to 100 MHz |
Yes, CM & DM |
50:50 |
USD 70 |
This will give a complete set of info which is as available on the product page/in manuals.
So as the anlysis of these figures availble, I can conclude that for most of the audiophile grade power conditioner manufacturer, the available specs are usless as they do not tell the whole story except for the Audioquest which tells specs only at Lab specs & not the real world scenarios.
Synergestic reseach is not publishing any spec at all even for their 28K unit which is criminal IMO. Considering the price of these units not disclosing the full specs can be considered very dubious. Whie Audioquest has discolsed their lab setting specs, they are sub-par and even $70 Schaffner filter has better noise reduction performance (which also specifies only lab condition vaues) which is the main function of all these units.
The only one to stand out of all these is EMI Filter by OnFilter, as they provide data for real world values instead of just Lab setting vaues & their performnce is very impressive indeed and that too at a lower price than all other audiophile counterparts.
Audio_phool
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