Unless I can prove to myself the filter/transformer is a good idea, I'l be going without.
So, it will be stranded 10-ga copper with an isolated ground, litz braided and run through grounded steel conduit to provide shielding from RFI.
Overkill? Probably. But these are things I can easily control, so why not? Cost increase will be far less than a decent pair of fancy speaker cables.
So, it will be stranded 10-ga copper with an isolated ground, litz braided and run through grounded steel conduit to provide shielding from RFI.
Overkill? Probably. But these are things I can easily control, so why not? Cost increase will be far less than a decent pair of fancy speaker cables.
An why not? That picture has a three phase breaker because I was lazy and didn't erase the rest, it works the same way with just one phase breaker.
But, hey, keep talking, I guess you are smarter than the ones that put together the electrical code in use in USA and Canada.
Why not!
It certainly won't hurt anything.
I wouldn't necessarily PAY someone else to do it; however I'm doing it, so it is just an extra hour of labor to braid up the wire.
Have you looked at the AC from the wall? If it's anything like that in my area, it's chock full of harmonics well past 20 kHz while still being within the local utility specification limits.
And your point is...? To add an UPS in the circuit to generate more HF noise?
And I live in a residential area, not in an industrial park. I have a transformer in the back of my yard that feeds via undergorund cables 6 houses. There is no 20kHz pushed in the power network from that feeder cable, unless your PC is generating it "in the house". That's why I advised to use a different phase for audio equipament.
OK, in my mind, litz wire is made from hundreds of small section wires and it is used when you are dealing with MHz range. There is no way you will braid that by hand!
At 60 Hz, the skin depth of a copper wire is about 1⁄3 inches (8.5 mm). That means that any conductoar smaller in diameter that that will carry 60Hz in the full section. #10AWG is much smaller that that!
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If you begged the question any harder I'ld offer a tin cup. I'm not in an industrial area, I've done this measurement at home and work, large harmonics start 120 Hz, as stated it's encapsulated in the local utility spec. My point is normal utilities can already be very dirty, you can't presume without measuring that all UPSs will make it worse.
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Hi SoNic_real_one,
Most are push-pull designs running at 60 Hz - the ones I'm used to anyway. The huge brutes that just keep on running as you replace sets of lead-acid batteries over the years. They were engineered to last eons, and deliver low distortion power. Probably lower distortion than what we get at our service these days. Any distortion that does occur is tough to get rid of. A common mode filter (at the least) would be required.
The units using HF switching to approximate a sine wave to a really excellent job. It's class "D" really, and they correct on a cycle by cycle basis. I'll bet these have better fidelity than the old brutes I like so much. They are far more efficient as well. The filtering of these high frequency components is pretty easily done. They are greatly removed from the output frequency (think of a D/A converter). If the audio gear uses an EI or "C" core, both with electrostatic shields, HF contamination is also reduced by a large amount. If the gear uses a toroid transformer, well then - too bad. Obviously not as highly engineered as they would have you believe (toroids being a wide band device).
Generally, I agree with you on this stuff.
Now one question. Why the devil is anyone discussing a GFI device? Its not required unless there is water within reach (by some distance decided by higher authorities). Last time I looked, water is bad for electricity - and audio equipment! One would wish to keep water and electricity separated as much as possible. I'm currently working on a Sansui 9090DB that was in a moist atmosphere for some time. It's hell, trouble everywhere, but it didn't look that bad aside from the metallic surfaces having white corrosion widely visible. I knew this one would burn me! The dolby circuit is the last (huge) issue now. I included this as an example of how destructive water vapor is to electronics. The situation is true, it's on my bench right now and giving me fits.
-Chris
Very true. Gas generators are even worse.
Of course, that depends greatly on the design of the UPS. Some aren't nearly as bad as this sounds, and you can also get great amounts of distortion on your mains if your outlet is wired down a chain. I have seen loose outlet connections, the use of the "poke in" contacts and loose Marr connectors. No doubt a DIY job, or a new house.
Well, let's look at that.
Most are push-pull designs running at 60 Hz - the ones I'm used to anyway. The huge brutes that just keep on running as you replace sets of lead-acid batteries over the years. They were engineered to last eons, and deliver low distortion power. Probably lower distortion than what we get at our service these days. Any distortion that does occur is tough to get rid of. A common mode filter (at the least) would be required.
The units using HF switching to approximate a sine wave to a really excellent job. It's class "D" really, and they correct on a cycle by cycle basis. I'll bet these have better fidelity than the old brutes I like so much. They are far more efficient as well. The filtering of these high frequency components is pretty easily done. They are greatly removed from the output frequency (think of a D/A converter). If the audio gear uses an EI or "C" core, both with electrostatic shields, HF contamination is also reduced by a large amount. If the gear uses a toroid transformer, well then - too bad. Obviously not as highly engineered as they would have you believe (toroids being a wide band device).
Generally, I agree with you on this stuff.
Now one question. Why the devil is anyone discussing a GFI device? Its not required unless there is water within reach (by some distance decided by higher authorities). Last time I looked, water is bad for electricity - and audio equipment! One would wish to keep water and electricity separated as much as possible. I'm currently working on a Sansui 9090DB that was in a moist atmosphere for some time. It's hell, trouble everywhere, but it didn't look that bad aside from the metallic surfaces having white corrosion widely visible. I knew this one would burn me! The dolby circuit is the last (huge) issue now. I included this as an example of how destructive water vapor is to electronics. The situation is true, it's on my bench right now and giving me fits.
-Chris
Are you having primary power source a gas generator? I am sorry, then audio fidelity is not your major problem.
The turbines in the nuclear power plants on the grid, they might be slow to react, but they don't need to because it is strenght in numbers
. When my load increases with 200W, that's maybe 5x10e-6 drop in the transport line voltage. Something like a 135dB PSRR? Yep, I can live with that.An UPS? Maybe 10-20dB??
Because I have kids in the house that might use the bathroom GFI receptacle to dry their hair (and I want to know they are safe)? Maybe because I know that "I didn't know, somebody on the net told me so" it is not an excuse in a court of law and I want to make people aware WHY it is illegal to have the electrical instalation in the house done "by the word of the mouth"?
Great observation. But urban legends about toroidal transformers are so strong, that almost nobody in DIY belive that a EI core is actually better for audio. If you point that to 80% of the people on this site, they try to lynch you for that
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.... irrelevant. Ignoring that you don't seem to be reading anything I wrote, have you ever done a spectral analysis at your wall plug?
Chris, having done those measurement I'll continue to disagree about toroids, at least on the basis of the parameter.
Probably a lot more knowledgeable people on this site than myself. Probably can tell you how much skin effect per MHz (I used to know that kind of stuff but when you are not in it for a while it just becomes useless information and gets tucked way in the back.) but I find that most of the time it is the basics that solve my problems.
With all the talk about UPS`s, sine wave shapes, twisted wire, nobody is mentioning what it is we are actually feeding with our power.
So tell me what portion of the sine wave is actually being used? The top 10%? If you are driving an amp really hard maybe the top 20%?
Basically it is how stiff your supply is, in this case a function of the utility company`s transformer and the wire resistance going to your amp. Forget the `dirty` power you are getting in. If you have a low wattage device you are basically cruising and just topping up the filter capacitors on the top of the sine wave wether it is dirty or not.
Now if you are pumping out a lot of power you are probably distorting the line more than anything else on that line. That 200w or 400w that you are putting out, do you think the power supply is drinking off the whole sine wave to get the juice it needs? Hardly. It is just loading down the tops of the 60 Hz.
So forget the idea of sine wave purity. You are feeding your amplifier with blips of power and they are nowhere near 60 Hz. The frequency spectrum of the current going through your diodes to your capacitors will have harmonics that would make a Marshall amp proud.
Do you know why we do not get all this buzzing coming through the speakers? Those big lovely capacitors the manufacturer (Or with some on here building their own equipment.) put in our power supplies. If you have an issue with RF put a good cap across your electrolytics, more than likely they are there already. If you have a problem with a light dimmer, I would spring for a axillary filter.
All this quibbling over what you are feeding your amps look like small change. Also braiding the power cables to protect from stray magnetic fields or to stop from transmitting them, doubt you could show it would be necessary. Any antenna designers out there?
As I said before, stick to a reasonable size wire, if you want to be good to your equipment put on a surge protector, and be done with it.
With all the talk about UPS`s, sine wave shapes, twisted wire, nobody is mentioning what it is we are actually feeding with our power.
So tell me what portion of the sine wave is actually being used? The top 10%? If you are driving an amp really hard maybe the top 20%?
Basically it is how stiff your supply is, in this case a function of the utility company`s transformer and the wire resistance going to your amp. Forget the `dirty` power you are getting in. If you have a low wattage device you are basically cruising and just topping up the filter capacitors on the top of the sine wave wether it is dirty or not.
Now if you are pumping out a lot of power you are probably distorting the line more than anything else on that line. That 200w or 400w that you are putting out, do you think the power supply is drinking off the whole sine wave to get the juice it needs? Hardly. It is just loading down the tops of the 60 Hz.
So forget the idea of sine wave purity. You are feeding your amplifier with blips of power and they are nowhere near 60 Hz. The frequency spectrum of the current going through your diodes to your capacitors will have harmonics that would make a Marshall amp proud.
Do you know why we do not get all this buzzing coming through the speakers? Those big lovely capacitors the manufacturer (Or with some on here building their own equipment.) put in our power supplies. If you have an issue with RF put a good cap across your electrolytics, more than likely they are there already. If you have a problem with a light dimmer, I would spring for a axillary filter.
All this quibbling over what you are feeding your amps look like small change. Also braiding the power cables to protect from stray magnetic fields or to stop from transmitting them, doubt you could show it would be necessary. Any antenna designers out there?
As I said before, stick to a reasonable size wire, if you want to be good to your equipment put on a surge protector, and be done with it.
Hi rdf,
What brand of toroid did you test? From my experience with these, they are normally a wide band device. I guess a manufacturer might be able to design that characteristic out, but I don't know enough to say one way or the other.
Did you post your tests anywhere? I am interested in your findings. Having said that, I'll continue to use EI core type power transformers for many reasons. I am curious to see how a toroid transformer performs for tube outputs. I'm talking about a transformer that was designed for the job of course!
You'll have no argument from me WRT your findings. To add, I have seen the harmonic content on my AC supply. It's variable in quality and can be pretty darned ugly.
Hi SoNic_real_one,
Your increased load will cause more of a drop simply due to IR losses, that and the finite impedance of your source. Yes, the drop will not be a lot, but the line distortion will increase as the conduction angle in a capacitor input filter is low.
A UPS losing 10 ~ 20 dB under a 200 watt load change has ceased to function. The sudden current draw causing this much drop will shut it down. The actual effect depends greatly on the output power rating, design and battery resistance and charge level. Remember the 3 KVA unit I mentioned? The one that had two additional battery packs? Adding a 200 watt load suddenly would not bother this fella too much at all. One of those power bar thingies would cave I bet.
Sorry, but I don't understand why a GFI would be considered as part of an upgrade for a service to power audio equipment. The remainder of your statement hinges on this comment, and is really both off topic and perhaps a bit on the defensive side.
Hi Printer2,
The repetition rate is normally at 120 Hz, unless there is a half wave rectifier which then creates a 60 Hz repetition rate. The bursts of noise will have a wide spectrum of frequencies.
So why are you crusading? It doesn't look like you have read th previous posts.
-Chris
What brand of toroid did you test? From my experience with these, they are normally a wide band device. I guess a manufacturer might be able to design that characteristic out, but I don't know enough to say one way or the other.
Did you post your tests anywhere? I am interested in your findings. Having said that, I'll continue to use EI core type power transformers for many reasons. I am curious to see how a toroid transformer performs for tube outputs. I'm talking about a transformer that was designed for the job of course!
You'll have no argument from me WRT your findings. To add, I have seen the harmonic content on my AC supply. It's variable in quality and can be pretty darned ugly.
Hi SoNic_real_one,
No, but I've often been tasked with cleaning up the destruction afterwards. Caribana used to be hard on amps because they were force to use gas generators on their floats.
A little exaggeration there to be sure.
Your increased load will cause more of a drop simply due to IR losses, that and the finite impedance of your source. Yes, the drop will not be a lot, but the line distortion will increase as the conduction angle in a capacitor input filter is low.
A UPS losing 10 ~ 20 dB under a 200 watt load change has ceased to function. The sudden current draw causing this much drop will shut it down. The actual effect depends greatly on the output power rating, design and battery resistance and charge level. Remember the 3 KVA unit I mentioned? The one that had two additional battery packs? Adding a 200 watt load suddenly would not bother this fella too much at all. One of those power bar thingies would cave I bet.
That entire line of thought is completely irrelevant. That's what I was commenting on. That is unless you have a stereo or radio in the bathroom... To each his / her own I guess.
Sorry, but I don't understand why a GFI would be considered as part of an upgrade for a service to power audio equipment. The remainder of your statement hinges on this comment, and is really both off topic and perhaps a bit on the defensive side.
Hi Printer2,
Not really. We have touched on that, and even pointed out that the wall supply is distorted due to the capacitor input type filter used most often.
The portion used is less than you may think. You can figure it out in terms of conduction angle in degrees. This will allow you to figure it out closely because you also know the frequency.
Only in the case of a power amp or really silly preamplifier. The dirty power that is referred to is higher frequency stuff that does tend to end up in the audio signal by way of the (generally) poorly designed power supplies in consumer equipment. It can matter.
Yes, that has been said a few times.
Those two concepts are not tied together. The HF noise on a since wave may possibly get into the internal circuitry. The equipment does load the peaks of the the wave form, and sometimes internal filtering is used to prevent that noise from getting out.
The repetition rate is normally at 120 Hz, unless there is a half wave rectifier which then creates a 60 Hz repetition rate. The bursts of noise will have a wide spectrum of frequencies.
Larger capacitors tend to create more problems. More is not always better, but it can make good ad copy.
And I'll try to make sure the lights are on the other phase before doing anything else.
Most AC power cable is twisted already. If you want to reduce noise pickup or radiation, buy a shielded cable (they make them).
Some surge protectors channel the HF hash onto the ground, that's not really where you want it to go. Also, all extra series resistance should be avoided. You even made that point earlier.
So why are you crusading? It doesn't look like you have read th previous posts.
-Chris
Jim,
I'd hate to see your big isolation transformer head to the scrap yard. Have you checked if it's a ferro-resonant type? They were popular with old computer systems, as they provided regulation as well as isolation. It will have a large capacitor and tertiary winding. Most ferro's have electrostatic shields between windings too.
I agree that power transformers generally pass through most noise and RF, but not all of them. Some are designed not to and it's worth checking an old beast for electrostatic shields/split-bobbin construction, that kind of thing.
I'd hate to see your big isolation transformer head to the scrap yard. Have you checked if it's a ferro-resonant type? They were popular with old computer systems, as they provided regulation as well as isolation. It will have a large capacitor and tertiary winding. Most ferro's have electrostatic shields between windings too.
I agree that power transformers generally pass through most noise and RF, but not all of them. Some are designed not to and it's worth checking an old beast for electrostatic shields/split-bobbin construction, that kind of thing.
I just read this entire thread. What an incredible lack of basic science understanding and even worse is disregard for the electrical code. Things like stranded wire inside copper water pipes?? This is the kind of thing that leads people to laugh at the "audiophools". Steel conduit magnetized? Have you ever even once seen this happen? And what are you gong to do? Bride the building inspector?
What you need to do is simple. The 20A dedicated circuit idea was good. Do that. But use just plain old "wire" But,... use oversized wire so the voltage drop is reduced. Tell yuo electrician to allow for NO MORE THAN 1%. He will know how to do this and it depends on the wire run length. Likely it means using #8 wire. This over size wire will keep the neutral very close to ground. That is about all you can ask of a household outlet.
Next, after construction is over, you buy, build or borrow a power line filter. These are basically just a 60Hz low pass filter. Plug it into your outlet and then plug your gear into that. The key is using just one outlet and one filter.
What you need to do is simple. The 20A dedicated circuit idea was good. Do that. But use just plain old "wire" But,... use oversized wire so the voltage drop is reduced. Tell yuo electrician to allow for NO MORE THAN 1%. He will know how to do this and it depends on the wire run length. Likely it means using #8 wire. This over size wire will keep the neutral very close to ground. That is about all you can ask of a household outlet.
Next, after construction is over, you buy, build or borrow a power line filter. These are basically just a 60Hz low pass filter. Plug it into your outlet and then plug your gear into that. The key is using just one outlet and one filter.
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