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Old 30th December 2012, 07:39 PM   #7911
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as far as I can tell the "Phihong" is a $1 generic chinese-made wall wart supply.
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Old 30th December 2012, 08:03 PM   #7912
bcarso is offline bcarso  United States
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Originally Posted by dvv View Post
Another revelation, huh? Just connect it, as there's no music without it?

Gimme a break ...

Brad, don't let yourself fall victim to sales blurb. Tell me, when have you connected whatever into your system and lived to have a revelation? Perhaps better, perhaps even much better (depending on what replaced what), but for God's sake, a REVELATION?

People so flaunt big words for little things ...

I've been reading such revelatory comments since the mid 70ies for whatnot.
Sorry my sarcasm wasn't more evident. Yes, it is a cheap d.c. non-switching wall wart from one of the world's major wall wart suppliers, and its only advantage is low primary-secondary capacitance. Since California essentially banned them in favor of cheap noisy switchers, we aren't allowed to buy them anymore here (they waste energy, supposedly, and the amount they do is tiny --- however, the law helped the coffers of such companies as Power Integrations immensely).

For me, this gushing review and the ilk are among the prime candidates for nasty tricks to be played on the reviewers. Never mind double blind --- just secretly sabotage their precious quantum devices etc. and let them suddenly notice, and tell you, that the music is missing. If they don't, tell them they are delusional and present proof.

Of course, don't expect them to ever speak to you again. As I mentioned in a thread, Dan Siefert tricked Enid Lumley once and got her to hear differences while he feigned, but actually didn't, make any changes. And she indeed never spoke to him again.
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Old 30th December 2012, 10:25 PM   #7913
fas42 is online now fas42  Australia
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Originally Posted by dvv View Post
And lastly, a somewhat obvious problem which few seem to think about is how the devices are connected to a filter. Remember, line noise is a part of the power drawn by devices on line which has been returned back into the grid. If you use a single filtering element, no matter which, for all the devices attached to the filter, then you do rid them of line borne noise, but you do NOT rid them of their neighbor's returned line noise, which as a source is right next to it. The obvious solution - each socket/device should have its own power filter, which protects it from both line noise and the noise generated by its first neighbors inside the same system.
The other flaw is, what about your human neighbour, what if he's using some really nasty electrical device which is injecting vicious harmonics into your power supply. One can hope distance attenuates most of it, but the residual may still be having an effect; if you can knock on his door, and suggest, politely, that he uses filters, and not get clobbered for your effrontery then you're ahead, .

Quote:
With a well made device, you will hear more spatial detail overall, and for some reason, especially front-to-back depth of the sound stage - beats me why this in particular, but there it is.
Because, front-to-back information is on every recording, but frequently is clouded over by what people call the "noise floor" -- this in reality is a type of distortion caused by interference, which mains noise is a major part of ...

Frank
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Old 31st December 2012, 12:10 AM   #7914
a.wayne is offline a.wayne  United States
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Not buying D , inquiring , when I'm ready to go , you better be too . The BURMESTER stuff was sworn to be worth every penny by associates who have them, i did try one of their 10gauge 12kilo power cord full of steel shot on my CD and bam ...!!!

No phocking way , so switched back to the original power cord and sure enuff it made a difference , a really worthwhile less digital thinness, less glare , fuller sound difference ..

So i was just looking deeper into this supply BS, of course you will know when i move on this ...



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Originally Posted by dvv View Post
On the Burmester conditioner - just carefully read the sales blurb and you'll notice some oddities. First they say it doesn't limit the current, and in the next paragraph they speak of 10A filters? Gimme a break ...

Wayne, I've been making power line filters (not "conditioners", these are rather classic passive filters, with a few twists) for 11 years now and I'm here to tell you that there hasn't been a filter or "conditioner" ever made which did not eventually limit the current passing through it. The question is not "does it", the question is "when does it start".

The other side of the coin are the audophiles buying them. They seem to think that say 10A of current is not ufficent for a CD player. I know this looks like an overstatement, but believe me, things like that are commonplace. Some 90% of any sales deal I ever made was explaining that the power drawn by a CD player translates to some 150-250 mA, so yes, 10A REALLY is quite enough.

Not to start myself on this, the key problem with line devices really is the fact that they can limit the available current. Obviously, this will happen only with power amplifiers, the rest of the system is not likely to need more than 1 A of current all told.

The most obvious reason for this is insuffiecent component power capability within a device, or relatively early transforemer core saturation. These two account for say 99% of all cases, and there are probably a few oddities here and there.

The other reason is not so obvious. It is related to the ground potential within a filtering device, which is a variable. If the filter is based on shunting noise to the ground, then its own efficiency will vary with the ground potential variance, making its performance a moving target.

And lastly, a somewhat obvious problem which few seem to think about is how the devices are connected to a filter. Remember, line noise is a part of the power drawn by devices on line which has been returned back into the grid. If you use a single filtering element, no matter which, for all the devices attached to the filter, then you do rid them of line borne noise, but you do NOT rid them of their neighbor's returned line noise, which as a source is right next to it. The obvious solution - each socket/device should have its own power filter, which protects it from both line noise and the noise generated by its first neighbors inside the same system.

ESPECIALLY valid for tube audio, because here we have an added source of noise - thermal noise.

The very odd thing (I find) is that it's the professionals who should see the logic first and understand it fully seem to be those who object most to power line devices quite a priori. They need a demonstartion to hear it at work before they accept that such devices are a MUCH better solution to CLC power supplies, which serve only their device, but leave the rest untouched. That, of course, assumes the power line filter has been done as it should have been done, and that means a pitifully small group overall.

With a well made device, you will hear more spatial detail overall, and for some reason, especially front-to-back depth of the sound stage - beats me why this in particular, but there it is. You will hear less noise, and your devices will use 5...10% less power from the grid, obviously heating less than before.

So, where's the problem? Well, I stand by everything I said, but must warn you - to really know how any device, for any money, will actually work or not, the ONLY way is to try it out in your system. Mine will always work and I guarantee that, BUT its overall effects vary from just barely noticeable to literally unbelievable, and including some very well known names (e.g. Krell, Audio Research, etc). Which is why I have a "loaner", a filter I give the prospective customer to try out in his system by himself, without me even present. Then, if he feels it's worth the price, he can order his. There were cases when I, quite frankly, would not buy my own filter simply because the effects were too small for the price - rare, but it did happen a few times.

To sum up - whatever you look at, Wayne old buddy, make damn sure you try it out before you buy it, or you stand to waste a lot of perfectly good money. You, with your Zero Ohm speakers, of all people here, could benefit the most, but for that to be so, you need to hear it first.

Sorry for the text length, but as someone actively involved in the field, I am very sensitive of snake oil pedllers, which somehow seem to be the most numerous.
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Old 31st December 2012, 12:25 AM   #7915
a.wayne is offline a.wayne  United States
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I wondered what happened to Enid , and this is all i could find

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Originally Posted by Enid
lots of rumors about enid, it seems. i heard she made her way to trinidad, colo for some sex change surgery and is now writing under the name "m. fremer." -kelly


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Originally Posted by bcarso View Post

As I mentioned in a thread, Dan Siefert tricked Enid Lumley once and got her to hear differences while he feigned, but actually didn't, make any changes. And she indeed never spoke to him again.
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Old 31st December 2012, 07:29 AM   #7916
dvv is offline dvv  Serbia
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Originally Posted by fas42 View Post
The other flaw is, what about your human neighbour, what if he's using some really nasty electrical device which is injecting vicious harmonics into your power supply. One can hope distance attenuates most of it, but the residual may still be having an effect; if you can knock on his door, and suggest, politely, that he uses filters, and not get clobbered for your effrontery then you're ahead, .


Because, front-to-back information is on every recording, but frequently is clouded over by what people call the "noise floor" -- this in reality is a type of distortion caused by interference, which mains noise is a major part of ...

Frank
Most of the time, Frank, people are simply ignorant of such problems and the power company gets the blame. When sonmebody's light flickers for a split second, ah, the damn power people are at it, while in fact, that was probebly somebody's fridge switching on, or a hot water boiler, an air con or a vacuum cleaner.

Honestly, this is not a problem they shoud be concerned with at all. They purchased whatever in good faith and that effect should be the device manufacturer's problem.

I still remember the time 12 years ago when a friend and I investigated line noise emanating from PC switchmode power supplies. My God, some of them were beyond belief, and only one really shined - I don't remember who the manufacturer was except that it was from Taiwan, and those people actually installed a return power line filter. Result - truly miniscule return values.

In my experience and research, the worst polluters out there are tube audio devices, and breathing down their neck are the PC switchmode supplies. Then come the usual suspects, things which use a starter cap to turn on.

Obviously, the power factor plays a strong role here - neon lights also use a starter cap, but they use like 9...20 VA, so they are not really noticeable beside a say hot water boiler, which will use like 1...2 kVA.

Most unfortunately, all this tends to build up over time and distance. The overall picture is catastrophic - try attaching your 'scope to the mains, set for bndwidth of 100 kHz and look at what's in there. The region between 5 and 50 kHz is not a jagged line, it's a rock solid opposing to the background pile of muck. In voltage terms, you will see peaks hitting 900 V here and there, and fortunately, they are short live, typically 1 mS or less - but they are there. If they took longer, we'd all be facing a lot of burnt out power supplies and probably a fair amount of burnt out devices.

You will also notice that by around 80 kHz, all the harmonics have settled down to lower values. Which makes filters like the IEC socket in-built one rather pointless, as their cutoff point is 600 kHz and above. They start to act when 99% of what should not be there has passed already.

MOST (please note the word, not all) audio engineers solve this problem by making CLC power supply sections. While this obviously works, it is, in my view, a half-baked approach only, because it leaves the power transformer and the bridge rectifiers still neck deep in dung. Whereas an external filter will protect them as well, ideally stopping most of the junk from ever even reaching the device, let alone upsetting anything.

The whole trick is to get them to listen to a well made device (rare but definitely available) and watch the 'scope screen without and with. Once they hear and see it at work, they might even acknowledge that you could be right.
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Old 31st December 2012, 07:31 AM   #7917
dvv is offline dvv  Serbia
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Originally Posted by mr_push_pull View Post
as far as I can tell the "Phihong" is a $1 generic chinese-made wall wart supply.
Those things usually have a small transforme, one 1N4007 diode and a filter cap 470-1,000 uF inside. And that's it. All of which are of junk quality.

As such, they are, plain and simple, junk that is best avoided.
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Old 31st December 2012, 07:39 AM   #7918
dvv is offline dvv  Serbia
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@brad

Sorry, I really didn't get it. But you already know what I'm most likely to say, and it is in tune with your sarcasm. Probably worse.

@wayne
A good approach. This is an interesting field, chock full of myth, magic and voodoo, second only to the cable manufacturers, I'm sad to say.

What you need is a line filter which is 100% symmetrical (nothing gets in, nothing gets out), uses a floating ground (which it creates and is thus totally independent of the main ground potential), can attenuate by at least 50 dB by 20 kHz (preferably more), has no significant come-back effects higher up the frequency scale and can pass at least 20 A on at least one of its outputs. A tall order, but it can be done, and in fact, it IS done.

The theory and practice for it has been established at least 70 years ago, I just tweaked it.
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Old 31st December 2012, 05:13 PM   #7919
bcarso is offline bcarso  United States
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Originally Posted by dvv View Post
Those things usually have a small transforme, one 1N4007 diode and a filter cap 470-1,000 uF inside. And that's it. All of which are of junk quality.

As such, they are, plain and simple, junk that is best avoided.
When I did ultra-cheap powered speakers (talking here of order 10 dollars for the entire bill of materials!) for Harman Multimedia, I typically used simple adapter transformers, no diodes/caps. It makes it far easier to accomplish quiet powerup/down, and as well it's more cost-effective to have the bulk cap close to the circuitry.

But usually the cheap d.c. output wall warts have a bridge, not a single diode, because it permits the transformer to have less core

When wall warts other than switchers were essentially outlawed in California, a lot of cheap powered speakers had to be modified from their original designs because the adapters induced so much more noise, owing to a much poorer degree of mains isolation.
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Old 31st December 2012, 05:28 PM   #7920
a.wayne is offline a.wayne  United States
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So are wall warts still available and recommended ...?

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Originally Posted by bcarso View Post
Sorry my sarcasm wasn't more evident. Yes, it is a


cheap d.c. non-switching wall wart from one of the world's major wall wart suppliers, and its only advantage is low primary-secondary capacitance. Since California essentially banned them in favor of cheap noisy switchers, we aren't allowed to buy them anymore here (they waste energy, supposedly, and the amount they do is tiny --- however, the law helped the coffers of such companies as Power Integrations immensely).

For me, this gushing review and the ilk are among the prime candidates for nasty tricks to be played on the reviewers. Never mind double blind --- just secretly sabotage their precious quantum devices etc. and let them suddenly notice, and tell you, that the music is missing. If they don't, tell them they are delusional and present proof.

Of course, don't expect them to ever speak to you again. As I mentioned in a thread, Dan Siefert tricked Enid Lumley once and got her to hear differences while he feigned, but actually didn't, make any changes. And she indeed never spoke to him again.
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