Y cap can be either L or N to G. You typically see both used in things like IEC inlet filters.
It does not mean both specifically. If it did you'd see two caps in one capsule, or at least they would say "capacitors" instead of "capacitor".
You can buy X1/X2 rated caps at almost any size. They are designed to fail in a manner that you don't have to worry about.
With 10uf you may want a discharge resistor to prevent surprises. The discharge resistor needs to be above 2kohm or it'll be trumped by the transformers. I'd have to check (in one of mine) but if I recall right 3kohm works, 2kohm negates a lot of positives.
Seriously try a 1ohm resistor in series with yours at home. You don't have any inductance in front of it, it can act as a path for junk that will radiate all over.
While little is set in stone with different mixing of power conditioning, typically, I have a decent idea after years of working on power conditioners. For example I know why and can solve problems with power conditioners that don't play nice with SMPS based devices.
The motor-start caps can be bought in many high voltages. But, just a thought.... those type caps are for intermittent current draw. So derate them for continuous duty.
Lately, these caps have been from foreign countries... like China and they do not last even with intermittent use. The one made by GE is my standard... now made in Mexico but still exactly as they were made in USA. Very reliable.
-Richard
-RM
Lately, these caps have been from foreign countries... like China and they do not last even with intermittent use. The one made by GE is my standard... now made in Mexico but still exactly as they were made in USA. Very reliable.
-Richard
-RM
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the secret in x-rated caps is the oxygen in the dielectric means less soot when it does arc over, which means less increase in leakage current.
The ultra high quality chassis for my amp with circuit designed by Dadod --- its fit and finish and milling all done....
My crew makes a great chassis only for great circuits.
-RM
My crew makes a great chassis only for great circuits.
-RM
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Motor run capacitors are intended for continuous use. I did a bit where I used a switched bank of them with an inductor to build a tuned AC power line filter. Very high circulating currents. Did clean up the line.
yes, you are correct... motor start are the intermittent use caps. John indicated he used motor start type. Be sure Not to use motor start type. use the motor run design.
-RM
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Hi Destroyer OS,
With good equipment, I have not heard the difference between power cords. I have heard many over the years, each said to impress immediately. They didn't.
Same deal with speaker wire. Only one that caused unhappy amplifiers sounded any different. Damn that guy with test equipment anyway!
If the equipment does have a flaw in the power supply, or a susceptibility to line carried noise, then you may very well hear a difference between cords. I have to admit that I haven't heard anything significant with that kind of equipment either.
I look at the power supply as something that isolates the circuits from the outside world while passing the energy they need to function properly. There are ways of accomplishing this goal with a comprehensive approach. It usually helps to reduce or eliminate the noise at the source. So a well designed piece of equipment takes all these things into account. If you need examples, just look at any good test equipment, warfare gear, space or astronomy equipment and you will find properly designed power supplies. Even batteries can be noisy compared to a good regulator.
-Chris
With good equipment, I have not heard the difference between power cords. I have heard many over the years, each said to impress immediately. They didn't.
Same deal with speaker wire. Only one that caused unhappy amplifiers sounded any different. Damn that guy with test equipment anyway!
If the equipment does have a flaw in the power supply, or a susceptibility to line carried noise, then you may very well hear a difference between cords. I have to admit that I haven't heard anything significant with that kind of equipment either.
I look at the power supply as something that isolates the circuits from the outside world while passing the energy they need to function properly. There are ways of accomplishing this goal with a comprehensive approach. It usually helps to reduce or eliminate the noise at the source. So a well designed piece of equipment takes all these things into account. If you need examples, just look at any good test equipment, warfare gear, space or astronomy equipment and you will find properly designed power supplies. Even batteries can be noisy compared to a good regulator.
-Chris
In isolation you are probably right. However in the matrix of connections that a typical audio system represents combined with the parasitic/leakage/etc. capacitance/coupling on the various links there are many ways for a power cord to have some effect.
I'm pretty skeptical but have demonstrated power cord effects to people even more skeptical than I am. The differences were quite audible. I don't know why.
I am very reluctant to use a line filter than has capacitive coupling to ground. It just makes all this worse. And do not give that ground connection any credence for noise reduction. It is never closer to a "ground" than a neutral wire. And with coupling effects 100' from the panel it probably has quite a bit of junk on it.
Probably the worst for noise issues is separate runs back to the panel for different audio devices. A good first step in setup would be to measure the chassis voltages between the audio stuff (source-dac-preamp-poweramp-speaker) before connecting them. Use a higher impedance voltmeter. The numbers can be surprising (I have seen as much as 90V with this test).
A good start to reduce AC power line noise problems is to specify power transformers that identify which AC line lead is the start of the winding and closest to the core. This in USA usage should be connected to the neutral or as it is now called the grounded conductor. Not to be confused with the safety ground.
Chris, the problem is, while I have heard a few pieces of gear that have zero changes for powercords... they also sounds terrible. Lab gear doesn't have to produce large watts, and it itself doesn't deal with swinging loads that change phase - it only measures them. I could go on, but need I? Since the 70's we have known all of that. Stuff designed like lab gear that is immune to everything, is immune to enjoyable sound.
I think Demain is correct. Simple fact is that it's all complex, and immunity is hard to get without 100% shielding - and that isn't perfect.
Subjective listening on Y and X caps will tell you a LOT. Obviously no one believes me, not even JC will try a simple 1 resistor experiment. In half the gear out there, they cause lots of noise radiation all over the place. For some they might prefer that sound...
I think Demain is correct. Simple fact is that it's all complex, and immunity is hard to get without 100% shielding - and that isn't perfect.
Subjective listening on Y and X caps will tell you a LOT. Obviously no one believes me, not even JC will try a simple 1 resistor experiment. In half the gear out there, they cause lots of noise radiation all over the place. For some they might prefer that sound...
It's funny, I have checked for subjective results on that, but still don't know if I chose the lower noise one on a common transformer I use 😀 The answer is, it isn't important since I got the best result.
Sorry OS, where did you want the 1 ohm resistor? In series with the cap to ground, or in series with the line?
Hi Demian,
Leakage current from the transformer and any other parts connected to the AC line.
As for test equipment, I've never listened to one. However, leakage currents and anything else that could cause trouble is lower than the audio equipment. If it wasn't, your noise floor would be a great deal higher.
When you mix different equipment they probably have treated the safety ground and common differently between them. Just because something is expensive doesn't mean the power connections are done correctly for the lowest noise and interaction. I think this would explain your observations.
-Chris
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Leakage current from the transformer and any other parts connected to the AC line.
As for test equipment, I've never listened to one. However, leakage currents and anything else that could cause trouble is lower than the audio equipment. If it wasn't, your noise floor would be a great deal higher.
When you mix different equipment they probably have treated the safety ground and common differently between them. Just because something is expensive doesn't mean the power connections are done correctly for the lowest noise and interaction. I think this would explain your observations.
-Chris
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