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Post by Deleted on Apr 23, 2017 4:57:31 GMT
As the P10 is an AC to DC to AC converter, I don't think a DC blocking circuit is necessary.
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Post by pinkie on Apr 23, 2017 6:14:44 GMT
Martin, I would be extremely careful with what you describe as a "white paper". Their description/title, not mine. At least, as you say, Nick has attempted an explanation. The problem with our subject is that it is, ultimately, subjective. Music is not much good if you don't listen to it. I'm an engineer and I like measurements and explanations but even so there is a point where we really cannot measure what we hear, we don't know how to. When I read cobblers from so-called measurists about specialist cables and mains treatments being unnecessary and all properly designed power supplies should be impervious to noise it makes me want to cry. Do these people never actually listen? Are their minds so closed that they truly cannot hear the bloody obvious effect a regenerator, a BMU or a better power cable has? Oops, sorry, rant over  There has been a debate on this subject on another forum. Even the most extreme measurements supporters agreed. The issue is not the ability to measure with instruments. The ability to demonstrate a difference can be heard in a proper blind test is sufficient. The fact that NOBODY EVER does, however bloody obvious the difference is claimed to be, reassures those who don't hear any difference themselves that their hearing is OK. And their minds are not closed, but free to accept the reality they experience. NOBODY EVER  |
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Post by Clive on Apr 23, 2017 8:07:32 GMT
I don't doubt usefulness of DC blockers. If the core of a TX is being saturated by DC with consequential buzzing it's not a good thing and it must surely have some negative effect on PS performance.
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Post by MartinT on Apr 23, 2017 8:20:03 GMT
The issue is not the ability to measure with instruments. The ability to demonstrate a difference can be heard in a proper blind test is sufficient. The fact that NOBODY EVER does, however bloody obvious the difference is claimed to be, reassures those who don't hear any difference themselves that their hearing is OK. And their minds are not closed, but free to accept the reality they experience. I really don't like blind/double-blind tests, they're artificial and create an atmosphere of 'must hear a difference or I'm useless'. They are frequently conducted on foreign systems with foreign music, with groups of unknown people and have the aforementioned pressure placed on them. I don't trust their outcomes any more than, say, Jon Atkinson of Stereophile. Then there are measurements. Very few of us indeed have the instrumentation that stands a chance of measuring such differences. That leaves us with using our ears. I am happy to continue to listen, swap back and forth, and come to a conclusion after relaxing with much familiar music. I can recommend a component or accessory based on my findings, and little else. I don't know how it will sound in other systems and that's where each individual must make a judgement call on whether to try it out for themselves, then conduct their own listening. |
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Post by John on Apr 23, 2017 8:22:28 GMT
Their description/title, not mine. At least, as you say, Nick has attempted an explanation. The problem with our subject is that it is, ultimately, subjective. Music is not much good if you don't listen to it. I'm an engineer and I like measurements and explanations but even so there is a point where we really cannot measure what we hear, we don't know how to. When I read cobblers from so-called measurists about specialist cables and mains treatments being unnecessary and all properly designed power supplies should be impervious to noise it makes me want to cry. Do these people never actually listen? Are their minds so closed that they truly cannot hear the bloody obvious effect a regenerator, a BMU or a better power cable has? Oops, sorry, rant over There has been a debate on this subject on another forum. Even the most extreme measurements supporters agreed. The issue is not the ability to measure with instruments. The ability to demonstrate a difference can be heard in a proper blind test is sufficient. The fact that NOBODY EVER does, however bloody obvious the difference is claimed to be, reassures those who don't hear any difference themselves that their hearing is OK. And their minds are not closed, but free to accept the reality they experience. NOBODY EVER Years ago I had a P500 unit My friend and I were trying different phonostages and forgot to plug the phonostage back into the reginarator. We both did not understand why it sounded so different for a few minutes until my friend remembered he plugged the phonostage into wall socket and not the P500 as soon we changed back to the P500 back came the soundstage and missing detail. I would describe this as a blind test without evening knowing it at the time as neither of us new a change had been made |
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Post by The Brookmeister on Apr 23, 2017 16:27:02 GMT
As the P10 is an AC to DC to AC converter, I don't think a DC blocking circuit is necessary. WRONG |
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Post by The Brookmeister on Apr 23, 2017 16:30:58 GMT
The issue is not the ability to measure with instruments. The ability to demonstrate a difference can be heard in a proper blind test is sufficient. The fact that NOBODY EVER does, however bloody obvious the difference is claimed to be, reassures those who don't hear any difference themselves that their hearing is OK. And their minds are not closed, but free to accept the reality they experience. I really don't like blind/double-blind tests, they're artificial and create an atmosphere of 'must hear a difference or I'm useless'. They are frequently conducted on foreign systems with foreign music, with groups of unknown people and have the aforementioned pressure placed on them. I don't trust their outcomes any more than, say, Jon Atkinson of Stereophile. Then there are measurements. Very few of us indeed have the instrumentation that stands a chance of measuring such differences. That leaves us with using our ears. I am happy to continue to listen, swap back and forth, and come to a conclusion after relaxing with much familiar music. I can recommend a component or accessory based on my findings, and little else. I don't know how it will sound in other systems and that's where each individual must make a judgement call on whether to try it out for themselves, then conduct their own listening. There will always be the punters who cannot afford one, whinge at the price of one, aren't even audiophiles but just like confrontation, like a good argument, have nothing better to do, hate dealers, won't pay full price for anything, expect retailers to be charities, I could go on but hey ho! No one forces anyone to buy anything apart from maybe food and drink to keep on living, the only listening test that is required is IN YOUR OWN SYSTEM, anything else is a usually a TOTAL waste of time. |
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Post by MartinT on Apr 23, 2017 16:44:01 GMT
As the P10 is an AC to DC to AC converter, I don't think a DC blocking circuit is necessary. Sorry, that's not how a P10 works at all. it's much cleverer than that, and uses a tracking amplifier that 'rides' the mains waveform, repairing it by comparing it with a reference waveform. Therefore, it's prone to DC as much as any other component with a big transformer. It also explains why the P10 is highly efficient and generates very little heat. In any case, I did all my listening with the DC blocker in circuit before my P10. |
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Post by Deleted on Apr 23, 2017 18:48:10 GMT
Taken from here - PS Audio P10 - How it works "The PerfectWave P10 Power Plant takes your incoming AC power and converts it to DC, similar to what comes out of a battery, and then with patented PS Audio technology regenerates and produces new sine-wave-perfect, regulated high current AC power. In the process of regeneration any problems on your power line such as low voltage, distorted waveforms, sagging power and noise are eliminated." Which would suggest it is an AC/DC/AC converter? |
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Post by MartinT on Apr 23, 2017 19:49:22 GMT
That's not how the P10 works, so their reference is to an older Power Plant or they've got it mixed up. If it converted all 1200W to DC and then back to AC, you could cook your meal on it. I've read their description of the circuit since before it was released and it's an inspired design. Of course, some power is converted to DC to run the circuits.
P.S. older Power Plants allowed you to change output frequency, the P5/P10 do not. This is because they modify the incoming mains waveform, not recreate it.
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Post by pinkie on Apr 24, 2017 6:06:31 GMT
I don't doubt usefulness of DC blockers. If the core of a TX is being saturated by DC with consequential buzzing it's not a good thing and it must surely have some negative effect on PS performance. The issue is not the DC per se, although blocking the DC may be the simplest fix. The core saturation arises because of over limit voltage. A positive DC offset can cause that, although it's real cause is a transformer not adequately specified for the normal anticipated supply voltage. A functional DC blocker can be built for a tenner. |
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Post by pinkie on Apr 24, 2017 6:19:00 GMT
As the P10 is an AC to DC to AC converter, I don't think a DC blocking circuit is necessary. Sorry, that's not how a P10 works at all. it's much cleverer than that, and uses a tracking amplifier that 'rides' the mains waveform, repairing it by comparing it with a reference waveform. Therefore, it's prone to DC as much as any other component with a big transformer. It also explains why the P10 is highly efficient and generates very little heat. In any case, I did all my listening with the DC blocker in circuit before my P10. Whilst I accept you may hear differences with anything you plug in regardless of the measurements, the discussion here is the presence or absence of DC on an AC waveform which is measurable. Did you measure the DC on the output of the P10 without the magic box plugged in? How many volts was it? |
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Post by pinkie on Apr 24, 2017 6:55:32 GMT
As the P10 is an AC to DC to AC converter, I don't think a DC blocking circuit is necessary. Sorry, that's not how a P10 works at all. it's much cleverer than that, and uses a tracking amplifier that 'rides' the mains waveform, repairing it by comparing it with a reference waveform. Therefore, it's prone to DC as much as any other component with a big transformer. It also explains why the P10 is highly efficient and generates very little heat. In any case, I did all my listening with the DC blocker in circuit before my P10. According to your earlier advice to Mike the P10 has a DC blocker and so it would be superfluous to use another one Jul 10, 2014 11:53:35 GMT 2 MartinT said: MikeMusic Avatar Jul 10, 2014 10:26:24 GMT 2 MikeMusic said: What's a DC blocker ? The P10 has one, so don't worry. "The PerfectWave P10 Power Plant takes your incoming AC power and converts it to DC, similar to what comes out of a battery, and then with patented PS Audio technology regenerates and produces new sine-wave-perfect, regulated high current AC power. In the process of regeneration any problems on your power line such as low voltage, distorted waveforms, sagging power and noise are eliminated." How its maker thinks a P10 worksNever let the truth get in the way of a good story A transformer will block DC. So any problems (there are none) with DC on mains will cease to exist upstream of the transformer in the equipment, which is pretty much the first thing the mains encounters (apart maybe from a beautiful fuse) |
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Post by MartinT on Apr 24, 2017 7:07:07 GMT
It's true, a transformer will block DC. However, the transformer's performance itself is impacted by DC.
I am astounded at the effect of a DC blocker on the P10, that should be evident in my review. It's another learning exercise.
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Post by pinkie on Apr 24, 2017 8:02:07 GMT
It's true, a transformer will block DC. However, the transformer's performance itself is impacted by DC. I am astounded at the effect of a DC blocker on the P10, that should be evident in my review. It's another learning exercise. In your 2014 post you told Mike that the P10 incorporates DC blocking and was unnecessary |
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Post by pinkie on Apr 24, 2017 8:03:21 GMT
However, the transformer's performance itself is impacted by DC. How? |
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Post by pinkie on Apr 24, 2017 8:15:17 GMT
Hey guys, let's not get this out of proportion. All we are talking about is a mains DC blocker. The only test here is, does it or does it not block direct current when only alternating current should be present. There is no rocket science here. This has been known about for years and Stratmanglers post shows an example of how simple a blocker circuit can and needs to be. Under those circumstances, I would suggest neither Nick or Dave (MCRU) are likely to make any commercial gain from the paper Nick has published. Personally I see it simply as an explanatory document for those wanting to understand what might be going on. Google DC blocker circuits and you will find you are overwhelmed by options, most of which could be introduced as a simple DIY project of you were so inclined. My previous post on this topic was in respect of Martin reporting a general improvement to sound which personally I question, but I do not dismiss. If that is Martin's experience, so beit. My personal view is DC on the mains can mess with your system and blocking it is a good thing as it stops that messing such as unwanted hum etc., something Martin never previously complained of as far as I am aware. Whether it brings a sound or listening improvement will have to remain in the head of the user. I can make no such claim other than when I fitted mine, stuff stopped buzzing, humming etc. That is why I advocate measure your mains first to see if you have DC present before you proceed further. Easy to do. Multimeter set to 250v DC. Probe across +ive and -ive mains supply. You should get a zero reading. Any reading in the positive indicates DC present and then it is worth considering how to block it. Some mains processors offer DC blocking as part of the package. I bought my BPS secondhand and being basic, it did not include DC blocking. I simply introduced a small component board to provide this. The higher grade products supplied by my manufacturer include it in these more refined BPS' I have to say, considering the price and quality of Martin's kit, the omitance of a DC blocking circuit is a bit surprising. Come on, come on, move along, move along, nothing to see here. Your BPS is a transformer. It must block DC. A blocking circuit could only be on the input to make any sense at all, and all it would do is prevent core saturation of an underspecified transformer. If the transformer is capable of handling the peak voltage including offset then a blocker will be of no benefit |
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Post by pre65 on Apr 24, 2017 8:27:05 GMT
Pinkie, have you read (and understood) the "white paper" that Nick Gorham wrote ?
It contains no marketing bullshit, just accurate facts and figures.
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Post by MikeMusic on Apr 24, 2017 8:34:22 GMT
Here's another stick on the fire
My Belles Monoblocks recently developed a noticeable hum. Worried me.
The hum came and went and came and went a couple more times
Mentioned this to Tony who said I needed a DC blocker, either in the Belles or the new Audio magic wonder box filter.
This never happened when running from the P10 - so does it have a *bit* of a DC blocker ....... ? K
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Post by pinkie on Apr 24, 2017 8:45:56 GMT
Pinkie, have you read (and understood) the "white paper" that Nick Gorham wrote ?
It contains no marketing bullshit, just accurate facts and figures. I skimmed it. Fair cop. Let's drop "how" for now, although I really meant "how does that affect the performance (measured or subjectively) of the equipment attached to it?), and Nick points out he hasn't attempted to test that. And we get back to that thorny old subject of "properly designed" I am intrigued that the P10 which used to generate such perfect waveforms, I rather took it as read that meant without DC offset, now needs a DC blocker to function correctly. |
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