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Post by MartinT on Apr 24, 2017 9:14:19 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 Richard I've just said "a transformer will block DC" and "it's a learning exercise". Clearly, the P10 does benefit from a DC blocker, despite it having a transformer. Which bit of this is hard to grasp? Am I not allowed to learn and gain experience as I go along, like any other person? |
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Post by MartinT on Apr 24, 2017 9:17:02 GMT
If the transformer is capable of handling the peak voltage including offset then a blocker will be of no benefit Wrong. Once again, this shows that you are making statements from opinion and not actually doing any listening. |
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Post by Greg on Apr 24, 2017 9:20:21 GMT
No, pinkie, what you meant was, "I'm going to have some fun and shit stir here." Go and do some research. Find out the facts. Find out why BPS manufacturers commonly fit DC blockers in their kit. When you've done that, I'll consider responding to your post.
PS. Writing multiple posts is not a way to avoid criticism of your usual long winded style.
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Post by MartinT on Apr 24, 2017 9:20:41 GMT
I am intrigued that the P10 which used to generate such perfect waveforms Trolling. No-one said the P10 or anything else was perfect. Equally, no-one has said the P10 didn't do a superb job before. What I have said is that the DC blocker improves it even more. Please refrain from making any further statements about the P10 unless and until you have heard one. |
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Post by John on Apr 24, 2017 10:00:36 GMT
Like any upgrade something like this might very from system to system so always best to try out first
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Post by pinkie on Apr 24, 2017 17:33:11 GMT
No, pinkie, what you meant was, "I'm going to have some fun and shit stir here." Go and do some research. Find out the facts. Find out why BPS manufacturers commonly fit DC blockers in their kit. When you've done that, I'll consider responding to your post. PS. Writing multiple posts is not a way to avoid criticism of your usual long winded style. Could you direct me to the information about why BPS manufacturers commonly fit DC blockers? Martin has confirmed that a transformer blocks DC. A BPS is just a centre tapped transformer Where do I find this information about "commonly fit DC blockers". Airlink and NVA don't appear to do so. |
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Post by MartinT on Apr 24, 2017 18:01:34 GMT
You don't need me to confirm anything. If you put DC into a transformer, what output would you expect?
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Post by pinkie on Apr 24, 2017 18:22:57 GMT
You don't need me to confirm anything. If you put DC into a transformer, what output would you expect? Yes. Thank you, I realise that. I was just noting it is generally accepted that transformers block DC, I have been unable to find evidence of balanced power being sold with DC blockers (one might suppose the fact that they are a transformer and therefore de facto block DC could explain that), and asking Greg for help with the research he had directed me to carry out. I should point out I have done some research on this. I have a poorly toleranced transformer in an active sub-woofer, which buzzes with transformer core saturation in some situations. I use a DC blocker, kindly supplied FOC by the manufacturer to fix this problem. But an engineer friend came round to DEMONSTRATE that this was over-voltage, and not DC per se. In my house, on my living room carpet, before my very eyes, he blocked the DC on the mains with a lab bench isolating transformer, and hey presto the buzz went. Then he added a VARIAC and increased the DC free AC voltage until the transformer buzzed. I heard the buzz stop and start with my own ears I make no comment about P10's performance - just share information from PS Audio's support (Paul McGowan) who states on their forum " Sounds like you have DC on your line. New fuses and the things you’ve tried to remedy it won’t be of any help. The good news is whatever’s connected to the P10 won’t have the same DC as the P10 will block any coming out of it. The bad news is the P10 itself will have hum until you can fix the issue. There are several things you can do, the easiest is to call the power company and have them measure it. Usually they will fix it if the DC is high enough, but it really depends on the utility."PS Audio support desk comment |
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Post by The Brookmeister on Apr 24, 2017 18:54:27 GMT
You don't need me to confirm anything. If you put DC into a transformer, what output would you expect? Yes. Thank you, I realise that. I was just noting it is generally accepted that transformers block DC, I have been unable to find evidence of balanced power being sold with DC blockers (one might suppose the fact that they are a transformer and therefore de facto block DC could explain that), and asking Greg for help with the research he had directed me to carry out. I should point out I have done some research on this. I have a poorly toleranced transformer in an active sub-woofer, which buzzes with transformer core saturation in some situations. I use a DC blocker, kindly supplied FOC by the manufacturer to fix this problem. But an engineer friend came round to DEMONSTRATE that this was over-voltage, and not DC per se. In my house, on my living room carpet, before my very eyes, he blocked the DC on the mains with a lab bench isolating transformer, and hey presto the buzz went. Then he added a VARIAC and increased the DC free AC voltage until the transformer buzzed. I heard the buzz stop and start with my own ears I make no comment about P10's performance - just share information from PS Audio's support (Paul McGowan) who states on their forum " Sounds like you have DC on your line. New fuses and the things you’ve tried to remedy it won’t be of any help. The good news is whatever’s connected to the P10 won’t have the same DC as the P10 will block any coming out of it. The bad news is the P10 itself will have hum until you can fix the issue. There are several things you can do, the easiest is to call the power company and have them measure it. Usually they will fix it if the DC is high enough, but it really depends on the utility."PS Audio support desk comment
And what's your point chief? I have sold maybe 5 or 6 P10's (I did not sell Martin his), out of those 6 sold four are now using a dc blocker to power it, there are also all the P10 owners who did not get their P10's from me who also use the dc blocker, maybe another 10 or so, NONE have sent them back under my 30 days return policy, ALL of them said things improved when they plugged it in. I prefer to let people HEAR it rather than debate about the technicalities of what DC on the mains is etc, etc, etc. Trust your ears. |
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Post by MartinT on Apr 24, 2017 20:03:07 GMT
The good news is whatever’s connected to the P10 won’t have the same DC as the P10 will block any coming out of it. The bad news is the P10 itself will have hum until you can fix the issue. Thank you for that. It exactly corroborates what I have been saying. The P10 is affected by DC. No DC is output by the P10. Pretty much sums it up. |
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Post by pinkie on Apr 25, 2017 6:39:35 GMT
The good news is whatever’s connected to the P10 won’t have the same DC as the P10 will block any coming out of it. The bad news is the P10 itself will have hum until you can fix the issue. Thank you for that. It exactly corroborates what I have been saying. The P10 is affected by DC. No DC is output by the P10. Pretty much sums it up. That's certainly one interpretation, but not I think the one PS Audio intended if you read the comment I quoted in the context of their support blog. Rather than direct you there, I think it said 1) The buzz from your $5000 device is not our fault it is the power companies for having too much DC on their supply 2) The buzz is the only issue which needs to be fixed and can be fixed by getting your power company to fix it, or using a DC blocker which we used to make but don't any more 3) The good news is the DC causing this problem won't affect equipment connected to the P10 (your hifi) because the P10 blocks the DC from getting to equipment connected to it Strictly, as noted previously with my friends practical demonstration, the issue is not DC, it is DC causing the peak of one half of the cycle to exceed saturation voltage and is basically a voltage level, transformer tolerance issue. (Well designed equipment has a transformer with a primary voltage capacity adequate for all "normal" - on specification tolerances - voltage supplies). The explanation, which involves a bit of calculus is here Core saturation - DCNone of the above says that you are not hearing great benefits in your system from using this device, which may have many wonderful properties for audio enhancement in the ears of the listener. That is subjective, and I recognise your right to your subjective opinion about what you hear. It is just to say it has nothing to do with blocking DC on the mains supply to the equipment you listen to music on. That is measurable. And the transformer saturation problem with DC is an over voltage one which can be explained and demonstrated |
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Post by Greg on Apr 25, 2017 8:04:12 GMT
It seems to me you are arguing for the sake of it. I will, however apologise for being incorrect about BPS manufacturers commonly fitting DC blockers to their units. You are correct, they do not. I was confusing the DC blocker with a soft start circuit which they do use.
you have pointed out that the cause is over voltage on a TX and that over voltage could be caused by DC. You have also acknowledged that even in your system, a DC blocker sorted out the hum on your sub-woofer and that such a circuit can be done for a tenner. So, regardless of what was demonstrated to you, a cheap and easily implemented circuit inclusion sorted your problem. That seems to me far easier to do than fitting another or a replacement TX or expecting the electricity company to sort it out. At the very least, DC on the mains could cause the TX in the P10 to hum/buzz. Regardless of whether or not that effects the music reproduction, who wants a buzzing power supply in their listening room?
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Post by MartinT on Apr 25, 2017 8:09:42 GMT
You (Richard) are reinterpreting facts to suit your story. Quite simply, this is what is happening:
- The DC blocker prevents DC from getting into the P10
- The P10 responds to the lack of DC offset by overall performing better
- The end equipment never did receive DC nor was claimed to
- The end equipment sounds better because the regenerator is performing better
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Post by pinkie on Apr 25, 2017 8:45:13 GMT
It seems to me you are arguing for the sake of it. I will, however apologise for being incorrect about BPS manufacturers commonly fitting DC blockers to their units. You are correct, they do not. I was confusing the DC blocker with a soft start circuit which they do use. you have pointed out that the cause is over voltage on a TX and that over voltage could be caused by DC. You have also acknowledged that even in your system, a DC blocker sorted out the hum on your sub-woofer and that such a circuit can be done for a tenner. So, regardless of what was demonstrated to you, a cheap and easily implemented circuit inclusion sorted your problem. That seems to me far easier to do than fitting another or a replacement TX or expecting the electricity company to sort it out. At the very least, DC on the mains could cause the TX in the P10 to hum/buzz. Regardless of whether or not that effects the music reproduction, who wants a buzzing power supply in their listening room? Absolutely. A DC blocker is a useful tool. It's a pity that there are not more, shall we say "entry level" products on the market. This thread has seriously got me thinking of producing one. But it fixes a specific problem, and a problem which really amounts to "fault conditions". Other devices, including BPS also fix it - unless like Martins P10, there are problems of core saturation in thedevices own transformers - again really "fault conditions". But with every fix come a series of complications, not least spending money. Using a DC blocker was the pragmatic solution to the under-specified transformer in my sub-woofer, and I agree completely that replacing the transformer instead would have been a sledge-hammer to crack a walnut (although even without DC it would hum at permitted maximum voltage) The power supply company point is worth bearing in mind if your supply is at a declared over-voltage, which I think was the presumption in the PS Audio blog. The EU sets voltage limits, upper and lower, which the power companies should supply, and which equipment manufacturers should design for. If your supply voltage is outside those limits, either below (brownout) or above, as a DC offset might cause, then that is a fault condition and you can require the power supply company to fix it. Within the required standard voltage range for your area, if you have a buzzing transformer, then it is down to you. But if the fault is with the power company, take it up with them. |
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Post by pinkie on Apr 25, 2017 8:49:51 GMT
You (Richard) are reinterpreting facts to suit your story. Quite simply, this is what is happening: - The DC blocker prevents DC from getting into the P10 - The P10 responds to the lack of DC offset by overall performing better - The end equipment never did receive DC nor was claimed to - The end equipment sounds better because the regenerator is performing better I'll contact PS Audio support for clarification |
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Post by Deleted on Apr 26, 2017 8:28:19 GMT
Some observations for you guys, the UK suffers greatly from DC offset, here in Buckinghamshire south we regularly see between 1.5~2.1Vdc sitting on the incoming mains (It should be ZERO, its AC!)
DC offset will cause many transformers to destabilise, and not being able to form the field (The humming / buzzing of a TX can without question be caused by dc) which can result in a down turn in SQ
Mike's mains for example were reading between 0.9 and 1.2Vdc yesterday (Surrey)some area's in the UK are affected more than others.
When dealing with mains be VERY careful, if an ANY doubt seek professional advice at all times.
With Martin's systems its interesting as his amplifier has a DC blockers built in so the rest of the system must be gaining benefit from having one in there.
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Post by MartinT on Apr 26, 2017 10:06:42 GMT
With Martin's systems its interesting as his amplifier has a DC blockers built in so the rest of the system must be gaining benefit from having one in there. Just a correction there, Tony. The P10 is getting the benefit of the DC blocker. I think the whole of the system is improved due to the P10 performance improvement, but unless there is something wrong none of the components were getting DC beforehand (my whole system runs from the P10). I will do a measurement of my DC on the mains when I get a chance, the last time I did it was at the old house. |
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Post by Deleted on Apr 26, 2017 11:15:17 GMT
Hi Martin
Had realised this, and was suggesting that the rest of the system is benefiting.
I fitted DC blockers to Mikes AM unit.
Again there are various DC blocking circuits, some are simple bridge rectification units on say the neutral line to more complex models with treatment for the block the live and neutral lines coupled with various capacitors.
Have heard many examples overs the years, some actually made the sound worse, a few did what they said on the tin, however I would suggest that the diodes/bridges used should be at least of 1000Vac capability (RMS of UK mains is 668Vac) and around 35 amps.
Better still they are genuine units available for fitting at the CU end (professional units)maybe worth investigating.
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Post by MartinT on Apr 26, 2017 11:26:49 GMT
Thanks, Tony. Nick's design is certainly doing the job and I am well pleased at the way the DC blocker and P10 together are powering the system.
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Post by pinkie on Apr 26, 2017 12:14:54 GMT
(RMS of UK mains is 668Vac) and around 35 amps. Sorry - I'm confused. Could you explain what you meant please? RMS nominal Vac for the mains is surely 240. Peak voltage is about 325. Maximum current on a conventional socket circuit on a consumer unit will be 15 amps. |
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