rickcr42
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Post by rickcr42 on Jul 13, 2006 3:33:35 GMT
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xerxes
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Post by xerxes on Jul 19, 2006 14:22:14 GMT
Hi Rick, I have a commercially bought "hi-fi" mains filter on my hi-fi and I'm very impressed with the improvement it makes to the sound. I was reading a couple of articles on mains fiters and wondering whether I could improve on it using isolation transformers in conjunction with a filter stage. Here are the articles: user.tninet.se/~hme893k/mt_audio_design/mt_audio_kits/mf_2001.htmwww.triode-systems.com/modules/wfsection/article.php?articleid=4From which I've come up with this: I was thinking of building a filter with 1 mains inlet and 4 mains outlets for low power components such as CD players, tuners, pre-amps etc. In the diagram I've just shown two outlets, but I could have 4 separate isolation transformers with chassis filters for each pair. In general what do you think, are these "off the shelf" filters any good? I was looking at this range at Rapid Electronics.Would it be better to have separate 6A filters in series in front of each separate isolation transformer? I was also wondering whether I could do something similar using larger 16A or 20A filters in front of a 500VA, or possibly 1000VA transformers for use with a power amp? RS components do this range of isolation transformers which may fit the bill.
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Post by jelosno on Jul 19, 2006 14:58:04 GMT
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xerxes
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Post by xerxes on Jul 19, 2006 15:23:05 GMT
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rickcr42
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Post by rickcr42 on Jul 19, 2006 17:10:18 GMT
Yes.Transformers isolate the line from a lot of crap that would otherwise find its way in with the only better method being those Mains AC-To-DC converters that sythesize a rock solid 60hz (50 hz to you ?) duiring the DC-back to-AC stage.Totally clean non varying mains power but expensive as hell (PS Audio and others) That MT link is interesting.Had not seen it before -looks cool the Triode Systems article similiar to the Hagerman design though I prefer the J.H. myself.Why ? Don't really know,i just do www.hagtech.com/pdf/conditioner.pdfOn your schemo I would personally lose the varistor.They don't play nice with others even though in damn near every single outlet junction box/lightening arrestor.Every time they are hit with a glitch the part deteriorates a little more until finally it is doing nothing but adding crap to the line. the rest ? Something like the MT Audio followed by the Hagerman device would be a nice combo Some say they hear a difference and I beleive them but I do not (and beleive they are all mostly made in the dsame factory anyway then rebranded).Just get the VA ratings right and those parts should work out fine bank breakers for sure but there is a LOT more going on the what you would think and more than just upgraded parts I beleive.The PS Audio products may be overpriced but they DO work. I just wish I knew how they get around the varistor/transorb (same thing ) issue and if that board somehow is also a "DC on the AC" blocker I have to agree in a way.If there is one area where the prices far outstrip the benefits it is the aftermarket cable industry and the AC Mains cleaning industry. Both are proven fields with audible consequences but sooo overpriced for what they do I more often than not take a pass until I can do the "Rick" version of.i just can not see paying more for accesories than my main system and when cleaing the AC lines means the cost is more than my power amp i will take a pass thanks ;D see above.It is really not that simple due to the way the MOV deteriorates a bit with every single mains line spike and that includes the little mini-events of daily non-electrical storm events but maybe the simple act of turning on the air conditioner ! As they go bad a lttle at a time they become audible as a source of noise in a hi res audio system and that is why so many power strips get a bad rap.Folks DO hear signal quality degradtion but are identifying the wrong culprit. I'm not sure if there is info on line about this signal butchering/degraded protection capability because my research was many many years ago and the source of my reading material with the info eludes me presently but if I find something will post it here.Very much was an eye opener for me who had everything plugged into such devices after I lost my first VCR due to a lightening pulse riding in BTW-the replacement technology is the Gas Discharge Tube.a lot more expensive but if you need it worth the added cost
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xerxes
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Post by xerxes on Jul 19, 2006 18:20:16 GMT
Plan B. Here's the inside of my Isol-8 mains filter: Outlets 1 and 2 are for amps, 3 and 4 for low power, non digital sources, like tuners and pre amps, 5 and 6 are for digital stuff, like CD players and DACs. I already know that I like the effect this has on my system, so I was wondering whether a neat upgrade would be to simply add four 100VA isolation transformers to outlets 3 to 6?
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rickcr42
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Post by rickcr42 on Jul 19, 2006 18:29:27 GMT
seems to me one big mamma at the input would do just as well since it is the Mains you are trying to clean up and not perform device to device isolation which would already happen with the AC step down power transofmers all audio devices use
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xerxes
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Post by xerxes on Jul 19, 2006 20:07:32 GMT
Actually, "one big mamma", lets say 1000VA, so that outputs 1 and 2 will allow for power amps to be connected, would cost more than four 100VA transformers. As it is, the 100VA transformers are too big to fit in the current case, but it would be faily straight forward to fit the exsisting PCB, four 100VA transformers and the sockets in a 3U rackmount chassis, which are available fairly cheaply. A larger 500 or 1000VA transformer wouldn't fit in the case with the PCB. I reckon I should be able to get a new case and the 4 transformers for around £140.00, which is very reasonable compared to some of the commercially available products. The MT Audio filter places the isolation transformer after the filter, so I wondered whether there is perhaps some benefit to doing it this way round. The Hagerman filter uses standard "off the shelf" filters, so I suppose that they are up to the job and I doubt there's that much benefit to building your own out of separate components. If I ever replace my integrated amp with a separate pre power combo, I may well try building a filter using one of these and a large 500 or 1000VA isolation transformer.
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rickcr42
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Post by rickcr42 on Jul 19, 2006 20:40:08 GMT
WTF ?
ANOTHER loooong post lost ?
man,i need to bounce and regroup before I set fire to the joint..................................
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xerxes
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Post by xerxes on Jul 19, 2006 20:49:57 GMT
It's sooooooooo annoying when that happens. I must spend too much time posting on forums, because I've got into the habit of copying my post text (ctrl+c) before hitting the submit button.
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rickcr42
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Post by rickcr42 on Jul 19, 2006 21:57:50 GMT
I do that usually right after losing a couple of posts (like now ) then after a bunch of successes get a bit lazy which is the signal for a WHAMMO !
LOST YOUR POST PUNK !
HOW YOU LIKE ME NOW ? event first they soften you up then drop the hammer.Same old story and one i fall for over and over and over and....................
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xerxes
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Post by xerxes on Jul 20, 2006 0:03:29 GMT
What was your loooooong post, I'm intrigued now. ;D I thought I'd play fast and loose with this post and didn't bother copying the text. Oooh, I just live for danger - extreme forum posting, totally radical man.
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rickcr42
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Post by rickcr42 on Jul 20, 2006 1:47:50 GMT
I was kind of hoping that would be overlooked but looks like I am busted and will now have to back up my post with something lucid...........dammit............ Going to live on the edge and wing this post. No net,nothing but pavement below so if it comes out crap can always say "the machine ate it" as an excuse for it going away (me deleting it later upon realising it makes zero sense ) Try the surplus electronics sites.Big time savings many times for those "one of" builds. Iron is always expensive and the larger it gets (VA) the higher the cost but there are for me adavantages to single over multiples. For one it is a lot easier to keep the grounds straight AND low in connection impedance which should be right at the mains inlet using commercial building code "approved" ground wires and connectors-the same type as would be used in any factory or other industrial setting for any machine controls where having a good safety ground can mean someone's life. I also find it easier to isolation mount the trafos and add a "DC on the AC" blocker,both AC trafos anti-buzzing precautions,when using a single main transformer rather than multiples.Just remeber if you go this route to use wiring up to the peak expected VA draw.If you personally prefer mutple trafos go for it man.your system,your way being president for life of Team cheap Bastard I am all the time looking for items that can with a little persuasion be used for high end audio and have used everything from breaker panel boxes to all steel control boxes (home depot ) to empty wooden wine boxes for my AC Mains BUSS. everything under one lid usually makes it easier to place with the weight of AC filtration/suppression usually being a nice rack stabiliser on the bottom shelf.all out would be a bank of outlets that are switched for audio componants you are in the habit of turning off when not in use (nice to have a single ON/OFF for all of them) and a bank unswitched for anything using a microproccessor or real time clock or circuit pre-heating.Filtered but always on PLUS one big honking power switch (circuit breaker) for a total system KILL just in case.The ultimate ? Illuminated AC Meter on the front panel switchable between volts/amps so i can see just what is going on.you would be surprised to see just how many sppikes and/or sags an AC mains line has in a single day ! I would shoot for both to gain another level of filtration.cascading filters does no harm that I know of though as with most things can/will reach a point where performance gains vs. cost becomes a wash. AC Inlet>Breaker or fuse>Common Mode RFI Filter>DC Blocker>Isolation Transformer(s)>Common Mode RFI Filters>Clean AC distribution out my attitude is they are all the same from the bottom feeder low cost units up to the more expensive with the only REAL difference being the label as long as you pre-select for peak VA+Headroom with only the "hand made with lovingly selecteds parts assembled by hand on a naked womans thighs" super expensive types offering anything different and may in fact be all made at the same factory then lablled according to who the customer is. This is not a deceptive business practice but usually no more than manufacturer backing with the "named" units and more "you are on your own" with the generics.Kind of like the old "I can buy a hammer for $3 yet the U.S. gov pays $300" without ever realising how many steps of testing that "same" hammer goes through and that the culls are what hit the retail store shelf while only the cherries go on to be used where a failed tool could mean someone dies (NASA,Military,Medical Industry) Just don't forget to put it in a cool box
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rickcr42
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Post by rickcr42 on Jul 20, 2006 4:37:39 GMT
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rickcr42
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Post by rickcr42 on Jul 20, 2006 13:15:23 GMT
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xerxes
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Post by xerxes on Jul 20, 2006 15:05:11 GMT
Hi Rick, You're going over my head as usual. I was wondering about selecting the correct size isolation transformers and came accross this formula: (W to VA) W ÷ 0.85 = VA (VA to W) VA × 0.85 = W I also came across this: www.powerstream.com/VA-Watts.htm, so I assume that 0.85 is the Power Factor, but if this isn't given in the transformer specifications, how do you determine it. The second article suggest that a PF of 0.6 is a standard assumtion, but I guessing that this is pretty low for an isolation transformer?? In any case, low power stuff, like CD players, mine is rated at 240v, 11w when playing, will be fine on a 100VA transformer which should allow for 60w to 85W draw, depending on whether you take 0.6 or 0.85 as the assumed PF; plenty to spare. However, My integraded amp can use up to 360W at full welly, which with an assumed PF of 0.85 is 423VA, but with an assumed PF or 0.6 jumps to 600VA. How much to you need in hand to be safe, or am I barking up the wrong tree with these calculations? By the way, I just wanted to say that I really appreciate you letting me pick your brains about this stuff. It's all very well searching around the web for articles and formulas, but there's no substitute for being able to ask someone for their opinion, or a specific question.
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rickcr42
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Post by rickcr42 on Jul 20, 2006 15:47:37 GMT
the quick and dirty is : Volts x Amps = watts So for example purposes 240 VAC X 5 Amps=1,200 Watts is the simple method What do you get if you divide the Watts by main voltage (*V) ? 5-the amps (A) so it is really not too bad a formula to get a baseling number once you get past the voodoo of electricity as modern alchemy (which it is-magic plain and simple ) I always assume the ratings are an average number because of the way appliances,thus consumer electronics, are rated for compliance with international standards but appliances are a steady state draw that does not vary except in the full "on" and full "off" states (much like digital,much like switching power supplies and why they are sonically inferior mostly). Audio signals are not just simple "on/off" steady state as with an electric "tool" but a dynamic signal that must respond instantaneously to any rapid changes,such changes anything from total zero to as high as the power reserves allow then back down to zero again while having most of their operation in the middle zone,the "average" power area between the extremes and all the while with different sections of the performance having differing moment to moment demands. When ALL these instruments/events just happen to climax at the same time is when you will appreciate the additional capability because it will be an effortless event (no strain having more than enough power) rather than one you take notice of because 'somethiong is different" and that different parts of the event changed to fit the constraints of the available power. Because of this we need to have enough headroom at all stages of power delivery (all audio is rewally) that says in laymans terms : All we expect and then some worst case plus a little so because of this it is good practice to get what is known as a ballpark figure then multiply X 2.5 to avoid either running out of enough power to respond to demands or running right at the limits which is always stressful and will result in parts expiring at worst or running hot at best-both conditions which are at the root cause of almost ALL equipment failure. you get it wrong from the outlet in the wall and no amount of amplifier power later can get it back ! Yes this is only the AC but it is THE working voltage everything else must use to reproduce the final signal if it is plugged into the wall. Mains Alternating Current is converted to a Direct current which means the varying sine wave is made into a single line of power.Anything that deviates from that STRAIGHT LINE is unwanted signal and is in fact noise,hum,ripple,RFI,etc. and why we go to such lengths to clean it up. This "LINE" is your audio signal just as much as the DC power supply is actually an audio signal because it is what you convert to a usable format to amplify or modify the audio signal input of whatever device. The old "garbage in garbage out" begins at the wall outlet which being a community device shared by everyone on your grid,and knowing how not everyone is a good neighbor,you attempt to build a "privacy" fence around your little corner of it and that is the mains filter
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rickcr42
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Post by rickcr42 on Jul 20, 2006 15:51:07 GMT
BTW-Ready for your daily "headache" Volts, Amps, and Watts: What are they?VoltageAll sources of electricity, such as batteries or generators, have the potential to do work (e.g. illuminate light bulbs, run electrical appliances). Voltage describes this potential. The greater the voltage, the more potential the electricity source has to do work. The potential to do work should not be confused with actually doing work. For instance, a battery that is sitting on a table but not connected to anything has a voltage, or the potential to do work such as lighting a light bulb. However, the battery will not light the bulb unless it is connected to the bulb in an electric circuit. Only then will the battery actually do work. The unit of voltage is the volt. One volt is defined as doing one joule (0.74 foot-pounds) of work to move one coulomb (6.25 x 1018) electrons. CurrentElectric current is simply the flow of electrons (or, in some cases, positive charges). In a circuit, current delivers energy from a source of electricity to an electrical device (e.g. a light bulb) or appliance. The unit of current is the ampere, or amp. An ampere is defined as having one coulomb (6.25 x 1018) electrons flow past a point in an electric circuit every second. The Relationship between Voltage and CurrentThe relationship between voltage and electric current is similar to the relationship between the height of a waterfall and the water that flows down it. A height is needed for the water to flow down the waterfall. The greater the height of the waterfall, the more energy the water has when it reaches the bottom. If no height exists, the water will not flow and it will not have any energy due to motion. A voltage (similar to height) is needed to cause an electric current to flow (think of cascading water) so that it can deliver energy to an electrical device or appliance. It is helpful to remember that a current is a flow of electrons and electrons have mass (therefore current is a mass of flowing electrons!). The higher the voltage, the more work an electric current can do. If no voltage exists, a current will not flow and work cannot be done. DC and AC CurrentThe current produced by sources of electricity comes in two main forms: direct current (DC) and alternating current (AC). Direct current is current that flows in one direction through a circuit. It is produced by sources of electricity whose positive (+) terminal always stays positive and negative (-) terminal always stays negative. For example, a battery produces direct current because the battery's terminals always remain the same; the negative terminal does not change to a positive terminal, and vice versa. Hence, the current will always flow from the negative terminal of the battery toward the positive terminal. Alternating current is current whose flow in a circuit periodically reverses direction. It is produced by a source of electricity whose positive and negative terminals switch or alternate back and forth. In other words, one terminal will switch from positive to negative and back to positive, while the other terminal will switch from negative to positive to negative. Alternating the terminals from positive to negative cause the current to flow in one direction, then in the reverse direction, and back to its original direction, and so on. Electrical generators in power plants throughout the United States produce alternating current that reverses direction 60 times per second. The unit used to describe the rate at which current alternates is the cycle per second, or hertz (HZ). Electric PowerIn general, power is defined as the rate at which work is done, or energy is used, per unit of time. Electric power specifically refers to the rate in which a source of electricity produces energy, or refers to the rate in which an electrical device, appliance, or piece of equipment converts electrical energy into other forms of energy. The faster a source of electricity (such as a generator) produces electrical energy, the greater its power output. The faster an electrical device (such as a light bulb) converts electrical energy in light and heat energy, the greater its power consumption. Electric power is related to voltage and current by the following formula: Power = Voltage x Current The unit of electrical power is the watt. One watt is defined as one joule (0.74 foot-pounds) per second, or one volt multiplied by one amp. Because the watt unit is used so frequently, electrical power is often referred to as wattage.
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xerxes
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Post by xerxes on Jul 20, 2006 17:22:02 GMT
Hmmm, Using your 2.5x safety margin: Power Factor 0.85: 360W/0.85PF x 2.5 = 1059VA Power Factor 0.6: 360W/0.6PF x 2.5 = 1500VA That's some hefty isolation transformers.
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rickcr42
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Post by rickcr42 on Jul 20, 2006 22:11:11 GMT
yup www.hammondmfg.com/5cline.htmwww.hammondmfg.com/5ccross.htmThis stuff is big,heavy,costly so why most often used where it does the most good-low level gain and digital stages. If anything I am paranoid about AC so tend to overkill because of the day to day and year by year "AC In Action" of the real world,at least my world. That world is one of power tools where I have seen some refuse to start,breakers break and AC extension cords or junction boxes melt when either more than one high current device was run simultaneously and there was not enough available power or worse,there IS enough power but it is being strangled by a cable far too long and far too light in guage thus it is heating up and melting from the heat of the overload if that overload is a continuous event. Or because of the long light guage cable a staple from a staple gun can not be fully seated in wood but must be finished off with a hammer yet as soon as the cable replaced with a much heavier and shorter cable CLACK ! Clean shot,fully sunk into the wood The are factual events that I have personally witnessed that were all corrected by allowing the AC Current bottle neck to open up by either increasing the size of the cables allowing a higher current to flow freely and/or adding another "box" (service) to the breaker panel for the higher current drains. So witnessing such events I can only conclude the same is true with AV gear with BTW the "V" of AV being much easier to prove because we can SEE it while with something as subjective as audio we are just not always sure we even know what we hear (thank the experts for that one.the brainwashing took ). My attitude is I have witnessed it in the field,have seen it visually on TV sets when something else in the home intruded on the AC line as noise (noise bars on the TV),or when there is a surge or worse a sag on the AC,have heard AC crap on my FM radio (and can tell when a thunderstorm is coming without looking at a weather report-crackle,crackle,crackle ) and MAYBE in some cases heard it though not entirely sure.Put all that together and the overkill looks less so. at least that is my story and I'm sticking to it
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xerxes
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Post by xerxes on Jul 20, 2006 23:34:30 GMT
Hi Rick, Looks like Hammond only make 115VAC versions, about as much use as a chocolate tea pot here in the UK. This is the range I was considering: www.clairtronic.com/controlpanel.pdfThere's no mention of the Power Factor, but the specifications for a similar range by another manufacturer suggested using a Power Factor of 0.8 as an approximation for calculating the rating required. With this in mind I was going to use two 100VA transformers and two 200VA transformers, one of each size on the digital filter outlets and one of each size on the analogue filter outlets. To give me two outputs for up to 32watts and two for up to 64watts, using your 2.5x safetey margin. That should be plenty for any CD player, DAC or active pre amp I might use. For the time being I'm going to leave the amp outlets without an isolation transformer. If and when I replace my existing integrated amp with a separate pre/power combination I will build a filter using the chassis type filters and select an isolation transformer to suit. Something like this perhaps for a pair of monoblock amps: It won't be cheap, but a lot cheaper than the commercially available solutions, and since getting the ISOL-8 filter I have, I'm a total believer in the positive effect mains filtering/conditioning has. The effect of the ISOL-8 filter was far from subtle, the mains must be pretty lousy where I live, and it had a positive effect which was at least as significant as changing an amp or a source component. Founder member, Team Overkill
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rickcr42
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Post by rickcr42 on Jul 21, 2006 1:14:50 GMT
at least a fire team leader BTW-I ever tell you about the story of how I founded Team Grado back about seven years ago before taking over team cheap bastard ? ;D no matter............ The main goal of DIY.That combined with the "have it your way" only custom designs afford which also invariably bangs down the cost by having an actual targeted use rather than a design that must foresee any potential usage that commercial devices must follow It is nice when every once in a while the hype surrounding a class of products has some actual teeth and cleaning up the AC mains is one of those where high priced as they are almost ALL do as advertised. Sidebar : This also came over from the medical industry to the audio where having stable glitch free voltages are a must for patient monitoring devices.There is no mystery why all of the first available high quality AC devices offered for audio use were called "Hospital Grade".Look to what works in life saving equipment and you will find superior audio as a side benefit more often than not The best you can hope for in an amplifier is for it to increase audio voltage without damaging the signal but since the amplifier itself can only translate the power supply voltage into an audio signal then if that is shit no amount of superior cicuitry will be able to fix it. Priority 1-get clean power Priority 2-amplify without changing the signal other than in amplitude Priority 3-make that amplifier non-responsive to any out of band undesirable signals (EMI,RFI,digital hash,etc) without screwing up priority 2 Simple right ? .
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xerxes
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Post by xerxes on Jul 21, 2006 14:56:25 GMT
It pays to shop around. I was going to order the isolation transformers from Rapid Electronics, but they were out of stock of the 100VA models and will only sell the 200VA models to account holders. Instead of mucking about I phoned the manufacturers; they will sell direct to the public and they are around half the price. Rapid price: £104 + VAT + Shipping Direct price: £47.60 + VAT + Shipping What a result!
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rickcr42
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Post by rickcr42 on Jul 21, 2006 15:33:47 GMT
Hell yes that is a good result.Better than 1/2 price new in the box is hard to beat with a stick
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rickcr42
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Post by rickcr42 on Jul 21, 2006 15:44:25 GMT
Quick TIP : Mechanically isolate the trafos from the chassis if you want to avoid conducted noise if the trafos starts to buzz (many do and moreso if some DC creeps into the AC).Rubber grommets or even a DIY luan//rubber/cork sandwich work well From Hammond :
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