I agree that in many cases, the cure of powerline conditioning is worse than the disease. However, some audio systems do benefit from such, and it appears the more issues that these systems have with powerline conditions or grounding, the more likely it is that the advantages of powerline conditioning will outweigh the disadvantages.
Many households have fairly distorted AC with goodly amounts of high-frequency components. Often the source of distortion comes from the outside environment, but just as frequently, much of the distortion is caused by household appliances like refrigerators, air-conditioning, inverter-type electrical heaters, big CRTs and video projectors, appliances with FLDs or logic circuits, and the switching power supplies found in most computers. Therefore, I normally recommend that powerline conditioning is used for everything _except_ the audio system, the idea being that the filters will stop high-frequency garbage from flowing back into the AC mains, and will keep the powerline conditions cleaner for the audio system. Due to the excellent primary-to-secondary isolation, R-core transformers are a strong asset when the AC powerline is not up to par. And due to the reverse - excellent secondary-to-primary isolation - R-core transformers are also an asset for high-current amplifier designs that use large amounts of capacitance.
However, many audiophiles power their systems from widely spaced AC wall sockets, which causes problems with grounding and exaggerates the effects of AC power polarity. This is a problem that needs to be solved by either running everything from balanced power transformers, or making up a centralized 6~8 outlet AC wall socket, running the entire system from there, and making sure that all of the component polarities are matched to give the lowest chassis voltage potentials. Normally, when I am doing system setups for audio shows, end-users, dealers, or audio reviewers, I carry around 3-outlet multiplier blocks that plug straight into the wall. When used in conjunction with a standard duplex AC outlet, two multiplier blocks give 6 outlets, which is enough for a simple audio system. The additional electrical contacts of the multipler blocks frequently will cause sonic issues of their own, and so I also keep all of the AC power contacts buffed and clean.
Assuming that the power transformers are capable of handling frequencies higher than 60Hz, without humming, buzzing or overheating, AC power regenerators with variable-frequency output will usually improve the sound. I have gone as high as 400Hz with good results. But it is a fact that many power transformers do not like AC frequencies much higher than 60Hz. Regarding the R-core transformers, they should be able to go up to 80~120Hz without problem.
Although it is true that power transformers are a major ingredient for improved sonic performance, I find that the filter capacitors have an even greater impact. My "baby" Connoisseur 4.0 preamp uses Kitamura 200VA R-cores (+/-50V dual secondaries) with Nichicon Super-Through electrolytics, while my larger Connoisseur 3.0 preamp uses custom amorphous-core cut-core power transformers (+/- 144V dual secondaries) and polypropylene capacitors. I've had identical-voltage versions of all of these components made up and done mix-n'match comparisons. In general, the amorphous-core transformer is clearly better than the R-core. But when I swap the Super-Through electrolytics for the polypropylene capacitor bank, there is a much greater, across-the-board sonic improvement. Actually, the R-core with polypropylene is sonically superior to the amorphous-core with Super-Through.
And the Super-Throughs aren't too shabby - possibly the best large electrolytic capacitor made today. But the polyprops are just so much better.
regards, jonathan carr
Many households have fairly distorted AC with goodly amounts of high-frequency components. Often the source of distortion comes from the outside environment, but just as frequently, much of the distortion is caused by household appliances like refrigerators, air-conditioning, inverter-type electrical heaters, big CRTs and video projectors, appliances with FLDs or logic circuits, and the switching power supplies found in most computers. Therefore, I normally recommend that powerline conditioning is used for everything _except_ the audio system, the idea being that the filters will stop high-frequency garbage from flowing back into the AC mains, and will keep the powerline conditions cleaner for the audio system. Due to the excellent primary-to-secondary isolation, R-core transformers are a strong asset when the AC powerline is not up to par. And due to the reverse - excellent secondary-to-primary isolation - R-core transformers are also an asset for high-current amplifier designs that use large amounts of capacitance.
However, many audiophiles power their systems from widely spaced AC wall sockets, which causes problems with grounding and exaggerates the effects of AC power polarity. This is a problem that needs to be solved by either running everything from balanced power transformers, or making up a centralized 6~8 outlet AC wall socket, running the entire system from there, and making sure that all of the component polarities are matched to give the lowest chassis voltage potentials. Normally, when I am doing system setups for audio shows, end-users, dealers, or audio reviewers, I carry around 3-outlet multiplier blocks that plug straight into the wall. When used in conjunction with a standard duplex AC outlet, two multiplier blocks give 6 outlets, which is enough for a simple audio system. The additional electrical contacts of the multipler blocks frequently will cause sonic issues of their own, and so I also keep all of the AC power contacts buffed and clean.
Assuming that the power transformers are capable of handling frequencies higher than 60Hz, without humming, buzzing or overheating, AC power regenerators with variable-frequency output will usually improve the sound. I have gone as high as 400Hz with good results. But it is a fact that many power transformers do not like AC frequencies much higher than 60Hz. Regarding the R-core transformers, they should be able to go up to 80~120Hz without problem.
Although it is true that power transformers are a major ingredient for improved sonic performance, I find that the filter capacitors have an even greater impact. My "baby" Connoisseur 4.0 preamp uses Kitamura 200VA R-cores (+/-50V dual secondaries) with Nichicon Super-Through electrolytics, while my larger Connoisseur 3.0 preamp uses custom amorphous-core cut-core power transformers (+/- 144V dual secondaries) and polypropylene capacitors. I've had identical-voltage versions of all of these components made up and done mix-n'match comparisons. In general, the amorphous-core transformer is clearly better than the R-core. But when I swap the Super-Through electrolytics for the polypropylene capacitor bank, there is a much greater, across-the-board sonic improvement. Actually, the R-core with polypropylene is sonically superior to the amorphous-core with Super-Through.
And the Super-Throughs aren't too shabby - possibly the best large electrolytic capacitor made today. But the polyprops are just so much better.
regards, jonathan carr
Thanks Peter,
Any idea what the "polypropylene capacitor bank" he refers to is??
I would like to research the mentioned poly caps! Any ideas? I will write him too.
Dominick
Any idea what the "polypropylene capacitor bank" he refers to is??
I would like to research the mentioned poly caps! Any ideas? I will write him too.
Dominick
You can see polypropylene capacitor bank in those pictures: http://www.lyraconnoisseur.com/page3.html
Re: PHRED AND PHOCKO.
Anyone know how the R-core compare in that respect? Banwidth is the reason I've been using EI this far, but if I can have that as well as elimination of EMI so I can skip on the shielding (not to mention cool-looking R-cores), that would be great.fdegrove said:
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