Hello, im wondering if some of you guys compared EMI / DC Filters and can suggest some, im trying to build a diy power distributor for relatively cheap (but still trying to make it "high-end" in terms of components and filters)
i found these two which look quite High End and im wondering what "experts" think about it
https://www.thel-audioworld.de/module/Netzfilter/Netzfilter.htm
https://775mv.com/product/power-emi-filter-for-audio-12a/
also i have a question:
is it worthwhile to put 1 central DC Filter and 1 EMI Filter for each socket (and between each emi filter a ferrite choke) or would it be enough to make for example one "Rail" for analogue and one "Rail" for digital devices?
i found these two which look quite High End and im wondering what "experts" think about it
https://www.thel-audioworld.de/module/Netzfilter/Netzfilter.htm
https://775mv.com/product/power-emi-filter-for-audio-12a/
also i have a question:
is it worthwhile to put 1 central DC Filter and 1 EMI Filter for each socket (and between each emi filter a ferrite choke) or would it be enough to make for example one "Rail" for analogue and one "Rail" for digital devices?
No one ? 🙁
i also found these audio emi filters on alibaba, are they any good compared to the more hifi ones ?
https://de.aliexpress.com/item/1005...3dc,tpp_buckets:668#2846#8110#315&pdp_ext_f={"sku_id"%3A"12000029780072790"%2C"sceneId"%3A"30050"%7D&pdp_npi=2%40dis%21EUR%2110.87%218.81%21%21%21%21%21%40211b5dec16669178209447093e2d62%2112000029780072790%21rec
i also found these audio emi filters on alibaba, are they any good compared to the more hifi ones ?
https://de.aliexpress.com/item/1005...3dc,tpp_buckets:668#2846#8110#315&pdp_ext_f={"sku_id"%3A"12000029780072790"%2C"sceneId"%3A"30050"%7D&pdp_npi=2%40dis%21EUR%2110.87%218.81%21%21%21%21%21%40211b5dec16669178209447093e2d62%2112000029780072790%21rec
If you want high-end performance then definitely you'll want filters dedicated to each outlet and you'll want to size those filters appropriately for the load current.
The aliexpress filters you linked are only available in 3 current ratings but for source components, preamp etc. you'll not need as much as 4A so that won't be optimum for lower powered devices. The 10A one should work fine for heavy-duty poweramps though.
To answer your question - I'd not bother with a DC blocker for each outlet but definitely an individual EMI filter based on loading for each.
The aliexpress filters you linked are only available in 3 current ratings but for source components, preamp etc. you'll not need as much as 4A so that won't be optimum for lower powered devices. The 10A one should work fine for heavy-duty poweramps though.
To answer your question - I'd not bother with a DC blocker for each outlet but definitely an individual EMI filter based on loading for each.
Hi I build such distributors and use ready made filters by the known brands. These are RF tight as well like they really should be if their purpose is reduction of HF/RF and not just emotions. When the "for audio" is used you pay too much, have a dangerous open frame filter but you'll see nice red audiophile caps. There is no high end in mains filters, there is guaranteed result needed and X and Y rated caps are mandatory. Problem is that filters should be adapted to the load and the frequencies expected so there is not a one size fits all solution. When using industrial EMI filters like the ones with built in IEC socket and fuse you have more or less good results when you choose a version adapted to the load. This is the simplest approach: a metal box with industrial mains entry with built in filter and fuse/switch. If the results are positive you could use industrial quality open frame filters per outlet of a lighter current rating but the casing needs to be larger, it will be more expensive etc. Nothing against the Chinese but the quality of Chinese made X and Y caps make one think they just stamp the letters on the caps because they have to. More than once I experienced blown/cracked X or Y caps in cheap Chinese made filters.
One filter for the whole group is OK (better than no filter anyway), 1 filter per outlet is even better when devices with internal SMPS are used. You'll need PE but you already needed that for safety anyway.
They are out of production of quite some years but Belkin PF30 were best in our tests of ready made distributors. Found one recently new in box but sold it. Well built, nice features, very good performance and fits esthetically with audio gear. If you can find one you have straight away very good results and these are safe as well.
*DC filters: it maybe is good to have just 1 outlet with a DC blocker as not every device suffers from sensitivity for DC components in mains voltage.
One filter for the whole group is OK (better than no filter anyway), 1 filter per outlet is even better when devices with internal SMPS are used. You'll need PE but you already needed that for safety anyway.
They are out of production of quite some years but Belkin PF30 were best in our tests of ready made distributors. Found one recently new in box but sold it. Well built, nice features, very good performance and fits esthetically with audio gear. If you can find one you have straight away very good results and these are safe as well.
*DC filters: it maybe is good to have just 1 outlet with a DC blocker as not every device suffers from sensitivity for DC components in mains voltage.
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Agreed the best starting point is a mains AC filter such has schaffner as the first step of incoming power . The smaller the current you'll get better performance but you may want to select a filter that works with the noise you have in the house. It should be noted these attenuate but don't remove completely - no filter removes completely but it's a great starting point.
Apart from DC chokes/inductors such as common or differential noise passives, I have been thinking if it's worth using high frequency opamps/transistors to neutralise noise spikes for low current as most voltage regulators target PSRR lower in the spectrum. If there's an RF PSRR regulator capable of working at higher speeds I would be interested. However most will add inductors to successively attenuate.
Apart from DC chokes/inductors such as common or differential noise passives, I have been thinking if it's worth using high frequency opamps/transistors to neutralise noise spikes for low current as most voltage regulators target PSRR lower in the spectrum. If there's an RF PSRR regulator capable of working at higher speeds I would be interested. However most will add inductors to successively attenuate.
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You are right about RF proof regulators (like LT3045) but nothing beats filtering passively first. What does not come in does not need to be processed. It is surprising that this gets so little attention while today the environment is chockfull of RF signals (by own choice). Even if the classic linear regulators would have lowest noise, they often are not very capable of RF. If you check various designs here you'll notice that most have no way of RF filtering at all. The measured performance is measured in a lab. This means that the design may perform differently depending on where it is used and performance is then a variable. Controversy is that such designs are also most popular 🙂 Even if one lives in a quiet area the home has LED lighting drivers, a wireless router, a smart phone with Bluetooth and wireless enabled etc.
What also is forgotten or ignored is that the load itself can be the EMI generating source feeding back to the mains voltage. My guilty pleasure is cheap but innovative class D devices and one gets to learn fast what emitted RF can cause. Not only they feed back on their own PSU, some also emit via the loudspeaker cables. Some of the questionable kind are excellent RF transmitters that can also amplify audio signals.
Some look at this with scepsis but a few simple tests in the own environment with EMI filters, ferrite beads, moving wireless stuff or disabling wireless and some measurements with an oscilloscope can be convincing.
What also is forgotten or ignored is that the load itself can be the EMI generating source feeding back to the mains voltage. My guilty pleasure is cheap but innovative class D devices and one gets to learn fast what emitted RF can cause. Not only they feed back on their own PSU, some also emit via the loudspeaker cables. Some of the questionable kind are excellent RF transmitters that can also amplify audio signals.
Some look at this with scepsis but a few simple tests in the own environment with EMI filters, ferrite beads, moving wireless stuff or disabling wireless and some measurements with an oscilloscope can be convincing.
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yes, i also heared differences with cheap powercords with integrated filters BUT i also heared those "reduced dynamics" many people talk about, thats why im in search to create my own filter with hopefully "high end" compenents that can compare to much more pricier ready made power filters (for audio)
to be honest the Thel-audio one sounds the best, the discription reads very interesting and it sounds like someone really tried to get the best out of it for audio purposes (for those that dont understand german)
also the dampening graphs look very convincing compared to other graphs i saw -> https://www.thel-audioworld.de/module/Netzfilter/EMI306Dat.jpg )
but yea, its quite expensive to put a 75euro filter on each outlet
im really interested in what people say about the thel-audio emi and dc filters, so if someone has some knowledge about good filter designs please take a look 🙂 im a bit "scared" about the china filters because i dont wanna end up finding out that those made sound quality wise things actually worse
right now im thinking about having 3 "rails",
one DC Filter on the input then it splits up into
1, a "unfiltered" Analog section for amps
2. one digital section for all digital devices related to audio (raspberry pi streamer, dac, preamp etc)
3. one "allround" section for all electrical devices other than audio stuff i have at my pc setup (for pc, monitors etc), this rail isnt actually for filtering stuff for the pc ac input BUT actually filter everything out for other rails, (so the analogue rail stays as clean as possible)
for other outlets inside the same room i will probably use a Auth EMX 506 filter which i still need to get and try also on my audio setup (it seems not as good as the thelaudio one from the graphs but probably better than nothing to keep crap out of my room (and specially the analogue "rail")
i think this approach gives me probably the best bang for the buck, what you think?
It sounds an awful lot like the German Einstein "The Octopus" filters. Have one here and it is a good device.
With filters it is not so much about sound but filtering unwanted HF/RF that may have impact on the sound. You may have better results using industrial filters and they are less expensive as well. I think nice graphs are nice but it is also a bit awkward as own products always seem to perform better than any other device. 75 per outlet really is absurd. You can make it as crazy as you like but I am sure you can end up with a mains filter costing more than the devices themselves. First of all you will need to know how polluted your mains voltage really is. Then how polluting your devices themselves are. If you only have transformer based devices you can maybe skip the group filters. If only incoming mains voltage is affected then you could get away with just 1 filter. Just imagine building an expensive mains distributor while your mains voltage and devices are both relatively clean....that would mean you have solved non existing issues.
I made a simple (but effective) one called "Fritz der Netzverteiler". https://www.diyaudio.com/community/threads/meet-fritz-der-netzverteiler.379850/#post-6859744
It feeds linear power supplies that have their own IEC inlet with filter. If your setup is like that you could use IEC mains filters at the PSU of each device. The big bonus here I that you can adapt each IEC inlet with filter exactly to the required current rating. There won't be a possibility of using a device on the wrong outlet and the distributor can be way smaller.
With filters it is not so much about sound but filtering unwanted HF/RF that may have impact on the sound. You may have better results using industrial filters and they are less expensive as well. I think nice graphs are nice but it is also a bit awkward as own products always seem to perform better than any other device. 75 per outlet really is absurd. You can make it as crazy as you like but I am sure you can end up with a mains filter costing more than the devices themselves. First of all you will need to know how polluted your mains voltage really is. Then how polluting your devices themselves are. If you only have transformer based devices you can maybe skip the group filters. If only incoming mains voltage is affected then you could get away with just 1 filter. Just imagine building an expensive mains distributor while your mains voltage and devices are both relatively clean....that would mean you have solved non existing issues.
I made a simple (but effective) one called "Fritz der Netzverteiler". https://www.diyaudio.com/community/threads/meet-fritz-der-netzverteiler.379850/#post-6859744
It feeds linear power supplies that have their own IEC inlet with filter. If your setup is like that you could use IEC mains filters at the PSU of each device. The big bonus here I that you can adapt each IEC inlet with filter exactly to the required current rating. There won't be a possibility of using a device on the wrong outlet and the distributor can be way smaller.
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ah nice! looks good 🙂 im not 100% sure yet but i will probably buy one of these and modify them https://www.thomann.de/de/the_tracks_racksteckdose_166.htm looks as a quite good (cheap) base module 🙂 other cases ready made for power distribution are in the 100 euro region (empty!)
(im kinda thinking of building a own rack for some time now, the 19" cases are not that expensive too with DIY streamer/Linear power supplys etc)
i dont really wanna "hard modify" existing devices like my active speakers, so im not sure if its a viable idea to change iec sockets for example
can you recommend some industrial filters in particular? unfortunaly im not really sure for what to look for exactly, "broadband" ones?
Broadband simply refers to the frequency range of attenuation. Most amps focus on 50 or 60Hz hum but the noise depends on the environment which will vary on location in the world (differing bands allocated for different purposes by the country regulator along with EMI/RF regulation) and the local environment of the device (electrical and radiated).
Suffice to say at this point blind guesswork if or what RF makes recommending a bit like blindly guessing. An RF spectrum analyser or scope will help identify bands of noise. After which you can selectively target the attenuation. The alternative is blanket attenuation (broad band) covering the RF frequency ranges in use within your country.
Radio, Mobile phone, SMPS, LED light power converters have regularly used frequency bands so broadly hitting those bands will help. Often broad band trades attenuation for the width of the band. Specific targeting of bands helps focus attenuation.
How effective chinese or EU or US own market designed attenuators are for other countries is debatable. It’s likely they have some use but may not be designed to target bands used by that local country.
Sounds like you may be better getting a professional audio line conditioner (such as those used by recording studios or touring bands).
Suffice to say at this point blind guesswork if or what RF makes recommending a bit like blindly guessing. An RF spectrum analyser or scope will help identify bands of noise. After which you can selectively target the attenuation. The alternative is blanket attenuation (broad band) covering the RF frequency ranges in use within your country.
Radio, Mobile phone, SMPS, LED light power converters have regularly used frequency bands so broadly hitting those bands will help. Often broad band trades attenuation for the width of the band. Specific targeting of bands helps focus attenuation.
How effective chinese or EU or US own market designed attenuators are for other countries is debatable. It’s likely they have some use but may not be designed to target bands used by that local country.
Sounds like you may be better getting a professional audio line conditioner (such as those used by recording studios or touring bands).
if you want such a casing, you can have one for free (just shipping).
I don't know about the Thomann device. Maybe I can put it this way: many simple items we were used to use for decades have meanwhile been replaced by far east produced equivalent looking stuff. This stuff is prone to defects even though there is a known brand name on it. Steel casings may rust within a few months, Schuko outlets may become brittle etc.
You can not go wrong with the classic German made parts made by Kopp etc. No hurry but I would buy quality goods while still available. Finding good quality switches is already harder than it used to be. Please try to find German made Schuko plugs with molded on good quality cable .... A well built mains distributor with quality Schuko outlets, mains switch and filters will be a 1 time only affair and it will possibly outlive you.
It is very viable, simple and effective to use for instance Corcom or Schaffner IEC inlets with RF tight container adapted to the respective load. It gives you skills in using a file. Hard modifying is effective, likely more effective than finding a one size fits all external solution. The thread title indicates you want the best 🙂
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A mains isolation transformer is a good thing as well as a filter.
As far as filter configuration, that may vary per the noise and your equipment.
As far as filter configuration, that may vary per the noise and your equipment.
i also considered this but they are rather expensive and im not sure what kind of filter is used, probably a generic cheap one which might work ok but im not sure if its "optimal", atleast the ones in my price region which would be up to 200-500 euro
i might come back to your offer depending on what i settle with, thanks for the offer 🙂
those iec inlet filters are not much different than the industrial ones encapsuled in a case with cable attachments are they?
the thing that keeps me away from the industrial ones are the fear of having not good sound quality in the end, for example the 0815 brennstuhl power distributors with filters i didnt really like, specially with my active speakers
i also considered those specially those with symetric -115V/+115V output, unfortunaly i dont know how they will sound in the end, i heared positive as well as negative reviews about it :/
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Did someone compare different filter solutions here? specially industrial filters vs "hifi" ones
would love to try one of those PS-Audio Power Plants but they are way to expensive for me 😀
If you consider Brennenstuhl to be an industrial good quality brand then you are right 🙂
* Strong warning against using symmetric -115V/+115V output stuff on AC equipment.
** I repaired PS Audio stuff. It is made for people that believe in stuff (probably influenced by "reviews") and decide on emotions/looks. That cheap Belkin PF30 was way better than expensive PS Audio distributors. If the focus is on "audiophile" you will end up with a nice looking unit with a nice name on it and superlatives about its perceived quality and its parts. Many a medical grade isolation transformer gives better results than audio stuff with high price tag. Industrial stuff that has no "for audio" tag will do its duty like it should.
* Strong warning against using symmetric -115V/+115V output stuff on AC equipment.
** I repaired PS Audio stuff. It is made for people that believe in stuff (probably influenced by "reviews") and decide on emotions/looks. That cheap Belkin PF30 was way better than expensive PS Audio distributors. If the focus is on "audiophile" you will end up with a nice looking unit with a nice name on it and superlatives about its perceived quality and its parts. Many a medical grade isolation transformer gives better results than audio stuff with high price tag. Industrial stuff that has no "for audio" tag will do its duty like it should.
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