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Post by eightdigitword on Apr 27, 2012 22:10:56 GMT
"This page is NOT for the people who don't know which end of the soldering iron to hold.
Don't kill yourself with electricity and above all - don't blame me. Leave your will at a lawyers office before embarking on the AC messing project."lampizator.eu/AC%20FILTER/SILK/FILTER.HTMLFor my AC filter distribution box i connected the mains supply directly to the common rail blocks with a grommet for the enclosure penetration. for the outlets i fitted x6 UK 1 gang sockets, fit as many sockets as you need. I did not fit a switch to the earth Parts list: suitable enclosure, plastic/wood: minimum size: 300 x 200 x 90 2.5mm Twin & Earth 6242YH, for UK plug to filter distribution box I found www.alertelectrical.com to be the cheapest at the time they sell by the meter and deliver quickly. UK 13 amp plug, X1 solid core 2,5 sqmm insulated wire for ring mains and socket outlets. Once separated I used the individual wire (with its insulation) to wire up inside the box. X10m needed www.tesco.com/direct/tower-twin-and-earth-cable-25mm-x-25m/212-6387.prd?skuId=212-6387&pageLevel=&sc_cmp=pcp_GSF__212-638713A 1 Gang Unswitched Socket White, x6 screw fix Product Code: 81723. check outside size of socket with enclosure before ordering either so that everything fits. Z16-12,12 way commoning block, X3, RS: 388-2855 PVC Black grommet, check that they suits the OD of the mains cable you will be using. (15.5mm Bag 100!, RS: 666-4600), SIOV Metal Oxide Varistor, 275Vrms 0.25W, X10 RS: 204-2062 MKS4 Polyester Cap,400Vdc,10nF X10, RS: 116-616 MKS4 Polyester Cap,400Vdc,100nF, X5 RS: 116-644 Ferrite rings, Maplin N87AB. bigger the better, X6 A glue gun recommended, www.ebay.co.uk/itm/MINI-HOT-MELT-GLUE-GUN-32-GLUE-STICKS-HOBBY-CRAFT-ADHESIVE-/120874309030?pt=UK_Crafts_Cardmaking_Scrapbooking_Glue_Tape_EH&hash=item1c24ab95a6 follow these instructions to build: www.audioasylum.com/audio/tweaks/messages/15981.htmluse pictures found here as a guide: lampizator.eu/AC%20FILTER/SILK/FILTER.HTMLSchematic: lampizator.eu/AC%20FILTER/SILK/SILK.HTMLSchematic shows wiring for one output only. Ignore L2,L3,L4. Switch on earth is optional, 1 output must be without a switch. Run your mains cable in to the box with Live, neutral and earth to one common rail each. Then connect each mains socket following the wiring shown in the schematic for each socket. twist all pairs of live and neutral together and follow Lukasz's instructions on winding round the ferrite exactly (parallel and 3 times round) If you read this and think that it might be beyond you then it is.
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Post by Deleted on Apr 27, 2012 22:50:06 GMT
Hi Eightdigitword great post and for those looking for a good inexpensive mains filter it's worth a try. it reminds me a little of the Swampy filter posted on WAD's forum some time ago which was quite highly thought of at the time. myself i have mixed feelings about using mains filters and my view is that those living in built up town or City areas may benefit most. i do filter the supply to my (Wills) Music PC and New DAC but for lower current and analogue stuff i tend to use an isolation transformer. (DAC's being the crossover exception) i also have a dedicated mains spur and use a mixture of Kimber and screened cables which I've accumulated over the years. thanks for posting this project as it's a subject that often gets ignored or dragged into an argument rather than properly explored. no chance of that hear though take care
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Post by eightdigitword on Apr 28, 2012 0:53:54 GMT
Hi Eightdigitword great post and for those looking for a good inexpensive mains filter it's worth a try. it reminds me a little of the Swampy filter posted on WAD's forum some time ago which was quite highly thought of at the time. myself i have mixed feelings about using mains filters and my view is that those living in built up town or City areas may benefit most. i do filter the supply to my (Wills) Music PC and New DAC but for lower current and analogue stuff i tend to use an isolation transformer. (DAC's being the crossover exception) i also have a dedicated mains spur and use a mixture of Kimber and screened cables which I've accumulated over the years. thanks for posting this project as it's a subject that often gets ignored or dragged into an argument rather than properly explored. no chance of that hear though take care Thanks Shaun, I live in the city in an old apartment building, I found a very prominent improvement to the sound using this filter unit. I believe in good designs and shy away from snake oil and over priced nonsense. this box gives a real improvement all with cheap parts. This unit is a must for anyone who doesn't already have a decent AC filter. I replaced my tacima CS929 with this unit and found a big difference. Its also an enjoyable project to make. I'll post pictures of my build, step by step once i get home.
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Post by Deleted on Apr 28, 2012 10:18:21 GMT
Hi Kevin? that step by step would be useful and most welcome. yup snake oil liberally applied in my case but the Kimbers where a gift so no expense wasted. I'm using the Tacima unit on my PC front end so I'll start the ball rolling on finding those parts and you're right it does look like fun. i live in a rural location so my supply is generally pretty clean but it has two weather dependent states. ON :-/or OFF windy weather causes power cuts here. but in some cases filtering can be useful to stop component interaction trough the mains. yup some components put spikes and other crap back into the mains (especially digital stuff and PC's). I'll look forward to seeing your project and will enjoy having a go at making my own. take care
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Post by eightdigitword on Apr 29, 2012 22:45:19 GMT
Hi Kevin? that step by step would be useful and most welcome. yup snake oil liberally applied in my case but the Kimbers where a gift so no expense wasted. I'm using the Tacima unit on my PC front end so I'll start the ball rolling on finding those parts and you're right it does look like fun. i live in a rural location so my supply is generally pretty clean but it has two weather dependent states. ON :-/or OFF windy weather causes power cuts here. but in some cases filtering can be useful to stop component interaction trough the mains. yup some components put spikes and other crap back into the mains (especially digital stuff and PC's). I'll look forward to seeing your project and will enjoy having a go at making my own. take care hey shaun, I'm trapped in the north sea right now! So I'll get those pictures added to this topic once i get home. I used an enclosure from maplins (LH41U). It took alot of dremmel work to suit the box to the six UK sockets and i needed to trim two socket ends to allow all six to sit snug. other than that the enclosure woked out well for the project. considering the lengths people go to with some upgrades this is a no brainer, infact this should be the first step. I like how it protects my gear too from spikes. Have fun!
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Post by eightdigitword on May 5, 2012 13:43:28 GMT
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Post by Deleted on May 5, 2012 13:48:23 GMT
Nice work Kevin
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Post by eightdigitword on May 5, 2012 14:14:26 GMT
Nice work Kevin Thanks! My only boo boo was on the centre sockets where i tried to trim them as the enclosure I picked was a tad too small. The plastic is super brittle and the edge of the socket shattered. Bit of cyanoacrylate and alls good again! wee bit of over hang on the sockets at the mains cable side too. smaller sockets/bigger enclosure would be best. well just better planning really! quite pleased with it and noticeable improvement in sound all round too. Although as pointed out by Shaun this will be dependant on how dirty your supply is. well worth it for the spike protection as the caps in my tacima 6-way were not accessible. This unit will allow me to swap them out every 12 months.
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Post by classicdelights on May 8, 2012 10:44:09 GMT
Kevin Many thanks for posting the full description and the photos. I will start by making a case and see where we go from there. I also have the X-10D upgrade kit from Mike so plenty to do at the moment. Best Regards Phil
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Post by Chris53 on May 8, 2012 18:23:35 GMT
Kevin This looks interesting. I seem to still be plagued with what appears to be dirty mains. The hifi sounds better in the early hours and yes I know I am hearing the difference and it is not my imagination as it is so marked - on bad days it almost hurts to listen to some discs which can then sound smooth at 3am). I have tried Isotek stuff ( Their Multway which is bottom of their old range) and I have a Belkin PF30. Neither make much difference. I have tried ferrite clamps on the mains cables and interconnects. I have recently read about how the cheap clamps (from places like Maplin) only affect RFI up to about 100Mhz and that you can get clamps from Farnells that go up to 2.5Ghz.. so I tried those on the mains cable (which are the shielded QED ones anyway) and my interconnects.. all this made no difference. So, .... and I'm finally getting to the point... Does this design do a better job than say the PF30 and all these clamps? Due to the low cost of it maybe I should just build one and find out, it would certainly be the cheapest thing so far. I am absolutely fine with the electrics of this but my RFI/EMI knowledge is somewhat lacking so I am curious as to how effective this would be.
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Post by Deleted on May 8, 2012 18:56:04 GMT
If you want to find out if it is the mains or not that is bothering you the simplest way would be to borrow or use a converter that is powered from a car battery or internal battery from a UPS.
This way you are completely isolated from the mains and if it still occurs you will at least know not to bother with (expensive) mains filtering. If the sound, using this device, is always the same (for better or worse) during the day and early hours you have proven to yourself it is the mains.
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Post by Chris53 on May 9, 2012 6:51:12 GMT
Well yes that would be a simple way if I knew where to borrow one from I've already tried a balanced mains transformer which did not solve the problem so would that have been isolated enough?
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Post by eightdigitword on May 9, 2012 11:11:07 GMT
Well yes that would be a simple way if I knew where to borrow one from I've already tried a balanced mains transformer which did not solve the problem so would that have been isolated enough? Hi Chris, I'm afraid my knowledge on filters and dirty mains is not enough to comment with authority. Solderdude is right the only definitive way to determine the source of this issue is to isolate each factor individually. Sounds to me like something near by is online during the day and shut down at night. Factory? Maplin sell a 12v inverter rated at 150W (you may need more than 150w) for £40, if you give the sales guy a good enough back story he may agree to a return. this with your car battery and possibly an adapter (cigarette socket to bare wire) would let you run your hifi from a battery for the purpose of a test and rule out the mains as the source. have you tested the sound form cold and from hot at both times? have you tried using different components, amp/source? Is there anything in your house that is on during the day and off at night that could be responsible? Is it year round? Is there set times? Do you have any enemies at the national grid? I would ignore individual ferrites (regardless of attenuation), fancy mains cables or swapping interconnects. My opinion is that ferrites should not be used on signal cables. Ferrites I have fitted to individual mains cables did not bring a noticeable improvement. The sum of the mains filter and the configuration in which it is wired did improve my sound. quite why or how is not something I have pursued. screened mains cable benefits border on placebo, though they are cheap enough to make at home and the peace of mind is worth it. I think cable layout probably makes a bigger difference. None of these factors could alter the sound to the extent you described. whether this mains filter will bring any improvement to your hifi is not possible to say without testing it in place. Neither would you know if this unit could remove whatever it is that is potentially degrading your mains without testing it. once all 'free' methods had been tested I would probably make the Lukasz filter anyway. After all if you find the source you'll still want a good filter. Also if the inverter proves its the mains you'll end up making the filter anyway to see if it removes it. either way you'll end up making the filter!
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Post by Deleted on May 9, 2012 12:05:42 GMT
I've already tried a balanced mains transformer which did not solve the problem so would that have been isolated enough? I agree with eightdigitword about this subject. A (balanced) isolation mains transformer can only address ground loop problems. For mains garbage (common mode, most garbage is common mode) they are 'transparent' in other words if RFI is indeed bothering you a transformer (balanced or a simple isolation transformer) will pass these devices unattenuated. A good (suitable) mains filter that adresses common mode AND differential mode RFI (with the ground connected to safety earth) followed by a (balanced) mains transformer followed by yet another screened mains filter with in this occasion the ground of the filter connected to the gear and the wires from the input and output kept WIDE away from each other in a metal box (connected to safety earth) would be very effective filtering even the highest contents of garbage on the mains. It could even be sprinkled with proper ferrites spread over various frequency bands. shielded mains wires do not prevent RF garbage passing through wires and could only pick up RF (capacitive or inductive) when cables with that on it run in parallel over large distances. They only 'shield' when the shield is properly connected to the mains (filter) and equipment it is connected to. They are 'invented' to prevent cables from emitting RF that is introduced by equipment (motor and motor controls/inverters e.t.c.) that are connected a certain distance from each other. In the 30 something years in audio (and electronics) I have never ever had to resort to those kind of measures though. Not even to pass the most fierce EMC tests I have done. a simple and proper filter is enough for that but of course isn't audio. Think off certain LED lights, FL lights, dodgy power supplies from TV, PC or cheap chinese products as most likely sources of RF garbage. Large machinery usually only shows by loud 'ticks'. If you don't notice ticks or sounds in your stereo system when playing with a light switch (so the light comes bearly on 'dimmed' and you hear sparks in the switch or for instance using an electric razor and holding in the mains plug just deep enough for it to spark it would be quite safe to say your equipment is filtered more than enough. I assume you already tested using portable equipment that can be battery and mains fed that is connected to the mains and disconnected while listening to differences. Hard to do with a CDP and speakers of course unless using an inverter of UPS. EMI/RFI/EMC is extremely difficult to tackle properly without specialised equipment such as RFI ananlysers/receivers. I (have to) deal with this shit often in my professional daily life and can tell you with great certainty that from a far one cannot see what the problem is and how to solve it.
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Post by Deleted on May 9, 2012 12:13:42 GMT
Frans Would using a simple open frame mains stepdown transformer, allow some of this garbage to be seen at the secondary of the transformer with a C.R.O. ? Alex
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Post by Deleted on May 9, 2012 12:20:11 GMT
It would isolate you from ground loops.
I had to resort to these measures quite a few times when repairing those older TV's. When you forgot to put it in and connected the CRO to your TV... sparks flying, fuses blowing and God forbid what else you took out in an attempt to repair.
To measure (show) the common mode garbage you would have to connect the ground input of the scope to safety ground somewhere and connect the centre pin of the scope channel to the transformer (if you know what you are doing and the scope can handle high voltages)
Usually current clamps are used to measure these signals with RFI receivers.
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Post by Deleted on May 9, 2012 12:27:14 GMT
Frans Been there, done that. I am aware of the use of current clamps, but I was trying to think of a way that might give some indication using perhaps a stepdown transformer in the spares box, or a cheap low VA transformer. Alex
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Post by Deleted on May 9, 2012 12:50:12 GMT
These transformers will limit the FR (possibly below 10kHz) for 'differential' signals. For common mode (most garbage is common mode) these transformers would simply pass most of the garbage above several 100's of kHz but in common mode only which means you cannot measure it on a scope input. The windings being close to each other in most trafos make up a good capacitor that passes (is close to a few Ohm) HF. (R-Core is best in that aspect, toroid worst unless it has a screen between primary and secondary windings that can be grounded)
power supplies may be low impedant between the power lines itself but in common mode the impedance is usually between 50 and 120 Ohm in general and this is what may cause certain effects in certain cases above a certain level.
To accurately measure certain levels with a CRO you must make sure the input impedance is also in that area and connected as in my previous post. Most scopes have 1MOhm inputs, some also 50 Ohm dummy's, those can be used.
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Post by Deleted on May 9, 2012 12:57:08 GMT
Frans Would you still see distorted /flat topped mains waveforms, but not higher order harmonics and HF garbage? Alex
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Post by Deleted on May 9, 2012 13:18:40 GMT
Flat topped waveforms are in the '1kHz' zone and would not affect much equipment. Most mains transformers can reach anywhere from 1 kHz to 30kHz in bandwidth. These go through the normal 'magnetic' route ( just like the mains 50/60Hz) and will be differential. They will be 'detected' in the rectifier and won't show up in the DC afterwards. Normal diodes can easily rectifie 1MHz signals and trafo's will not go above 10kHz in most cases.
They will not show up in common mode (clamp) measurements eiether.
The Harmonics, or higher frequency artifacts, that are emitted by equipment that can cause this flattening of mains (devices that draw a lot of power) are the nasty buggers and RF is mostly common mode. Since those 'around a few kHz' short peaks would be repetitional in a 100Hz rythm you would be hearing a 'sharp noisy' hum. Like when you hold your finger on the RCA input type of thing.
The RF garbage would probably show up in the CRO trace as soon as you connected the ground connection and perhaps vary only marginal when connecting the centre pin. (If this is what you mean)
For those that want to know what common mode is (not for you Alex, you already know).
a common mode signal is a voltage/current that is superimposed on BOTH powerlines and equal in phase and amplitude. It is not present between those 2 lines because they cancel each other out. It IS present between the power lines and the 'ground' we walk on though.
Mains (or any AC/DC voltage) is present between 2 lines. Even if one of these lines is connected to 'ground' as is the case with mains wher one wire is live and the other neutral the common mode stuff will still be equally present in amplitude on both lines with respect to the 'ground' we walk on.
The common mode signals ONLY become a problem in some equipment and depends on how it is connected and how the internals (wiring and PCB layout) are made and what parts are used and how.
If your equipment picks up a phone that is BEING called and is situated closer than 30cm it is likely to be also sensitive to common mode crap on the powerlines. If you hear nothing, not even when held directly to it chances are the device in question is not sensitive to 900MHz or 1.8GHz but may still very well be sensitive to other frequencies so doesn't say a lot.
To determine if something is sensitive you really need specialised equipment and someone who knows how to operate those devices and get meaningfull measurements.... ON SITE or in the lab the conditions may vary considerably.
Very complicated matter.
difficult to explain without (moving) pictures. I am sure common mode is explained on the web as well.
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Post by Chris53 on May 9, 2012 17:50:16 GMT
Thanks for all the input There doesn't seem to be a factory or anything that obvious nearby causing this. Nothing in my house either. I thought for a while it might have something to do with my neighbour but they have been on holiday for 10 days and the problem is still there. It doesn't seem to have much to do with equipment warming up as switching it on from cold at 3 or 4am usually results in pretty good sound with the problem virtually gone. I've tried different headphone amps and two different CD players and the problem is pretty consistent. As far as I know I don't have any enemies at the national grid. The inverter sounds like an interesting experiment and I am going to try Frans idea of playing with my light switches to get a better idea of what the problem is.
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Post by Deleted on May 9, 2012 21:18:35 GMT
Chris A longshot. Do you have any LED lighting, or perhaps compact fluoro lights switched on ? Some earlier types of LED lighting emit a large amount of garbage, as Mike can testify. Alex
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Post by Chris53 on May 10, 2012 5:45:26 GMT
Chris A longshot. Do you have any LED lighting, or perhaps compact fluoro lights switched on ? Some earlier types of LED lighting emit a large amount of garbage, as Mike can testify. Alex Alex No, nothing like that. It doesn't seem to be anything in my house causing the problem. At 11pm, even 12pm or 1 am it isn't as good as it gets at 3 or 4am. Someone in the area has something that affects it (I guess) but it doesn't seem to be my next door neighbour who has been away for 10 days... unless he has something that switches off automatically at around that time. I remember he used to have a fish tank so perhaps the lighting of that is on until late. I should ask him perhaps...
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Post by Chris53 on May 10, 2012 6:58:20 GMT
A footnote:
It sounded great at about 3am this morning again. The effect on the sound when it sounds horrible is like the midrange is being pushed forward. When it's really bad it almost schreeches at you. There are a number of things that I play to test this out and they all sound sweet at 3am.
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Post by Deleted on May 10, 2012 7:27:06 GMT
Chris
Are you 100% certain that it isn't temperature related ?
Alex
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