New Power Cable test proposal

Hi,

purplepleaser said:
Keeping it simple attracts more tester,which in turn gives more results to compare and you get the best conclusion in the shortest time scale.

Keeping it simple simply makes sure that if the data is not extremely conclusive (it rarely is in testing "fringe" items, for many reasons) you need to demonstrate that your test actually has significance and statistical power.

1,000 Testers who all have failed to hear a difference, but have failed to illustrate that they can actually correctly identify small but clearly audible differences are worth a hill of beans full of weevils.

10 Testers who show clearly that they can clearly hear small differences such as previously described, but fail to hear "mainscables" carry a significant weight.

Also, on the other hand, many people are not quite adept to systematic listening for differences. You might include a CD which has only A/B tracks, clearly identified and includes notes for listeners how to learn to listen analytically and to identify reliably these items signted, prior to them taking the abx CD test and testing the cables.

So, you may have lower numbers, but your results, regardless which way they go, will be much more relevant and significant.

But as said, your call.

Ciao T
 
Hi,

mosfet said:
This cable from Supra is approved to HD 21.5.3 ââ'¬Å"Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 Vââ'¬Â under the low voltage equipment directive.

CT-125 and equivalent tends to be rated 600V RMS and RG-213/214 et al is rated for 20KV under a wide range of standards!!!!!

Compared to RG-213/214 what you cite is capable of much less.

You may know which standar to cite, but clearly you do not know what it means. The absence of an explicit mains-grade cettification simply means it was not applied for, not that the certification could not be attained....

L8er T
 
Last edited by a moderator:
The absence of an explicit mains-grade cettification simply means it was not applied for, not that the certification could not be attained....

More potentially dangerous misinformation. You really should pack this in.

Perhaps an email to the HSE or IEE enquiring of their opinion on connecting domestic appliances to the mains supply with RF aerial cable would be in order?
 
Hi,

mosfet said:
Perhaps an email to the HSE or IEE enquiring of their opinion on connecting domestic appliances to the mains supply with RF aerial cable would be in order?

Please be specific as to the exact cable type and the actual use. Otherwise you may think you are talking about 300 Ohm twinax...

L8er T
 
Please be specific as to the exact cable type and the actual use. Otherwise you may think you are talking about 300 Ohm twinax...

Of course. Could you specify this now so there is no room for misunderstanding? Alternately I can take the information as presented on the website.

If this is an amicable and agreeable way to resolve the disagreement of opinion.
 
mosfet said:
Of course. Could you specify this now so there is no room for misunderstanding? Alternately I can take the information as presented on the website.

If you include ALL the information, that is you perhaps instead on selective quoting use merely a link to the webpage I'll live with that just fine. It's been out there for seven odd years and will probably still be there a few years from now.

L8er T
 
I'd be interested in taking part - it may be flawed but is very worthwhile, imo and I'd be very interested in the results based on my own system at home.

How long would we get the cables for ?
 
griffo104 said:
I'd be interested in taking part - it may be flawed but is very worthwhile, imo and I'd be very interested in the results based on my own system at home.

How long would we get the cables for ?


Hi, Thanks for the interest.You may only get the cables for two-three days depends on the amount of tester 3dsonics scares away.This test may be flawed but at least you a willing to try something not like 3d Big on typing small on action(offering services to the test.)
Cheers Lee ;)
 
TEST:
Simple as this for me...

Get a very cheap lead with no oxidisation. Get one VERY expensive lead (top of the range). Run a test with the same CD over and over (blind). See if you can tell the difference.

For 20 (ish) or more blind tests the person should change the mains cable at random.

Scoring will be:
Better, Worse, can't tell.

-----------------------------------------------------------
Cable 1 Cable 2 Cable 3
-----------------------------------------------------------
Nordost Cheapo Cheapo --- Not known to the listenners.
-----------------------------------------------------------
Better Worse Worse
-----------------------------------------------------------

With lots of people!....

In terms of better or worse:
if you preferred the cheap cable this would consistently come out as better for that ONE person.
if you preferred the expensive cable this would consistently come out as better for that ONE person.

Score of can't tell will be useful as well.

I would expect with the vast differences claimed that the percentage chance of preffering one cable over another is high. If not it'll be a 50\50 split and if the cheap cable wins I'll laugh.

What do you all think?
 
3DSonics said:
I have organised quite a few blind tests myself. I am merely pointing out the issues you should consider. BTB, I have just done a similar "send out a bunch of different cables" test, for market research in the context of my own interconnect designs. The results suggest not only that people could hear a difference, but also that they preferred in general the same design. But you will not find me publishing the results, I had enough running battles on that subject.

Ciao T
Unpublished results have no meaning. If you are really so confident that you know how to design and organise better study then the first attempted by HifiWigwam then let us see them.
 
3DSonics wrote:
Note, the SPECIFIC cable described in TNT Audio, WHEN CONSTRUCTED COMPETENTLY AS DETAILED are electrically safe
If you include ALL the information, that is you perhaps instead on selective quoting use merely a link to the webpage I'll live with that just fine.

Enquiry submitted to the Health & Safety Executive by email
http://www.hse.gov.uk/contact/ask.htm


Dear Sirs

Please could you tell me if it safe to use co-axial satellite cable as a replacement for a standard electrical mains lead for connecting my hi-fi equipment to the mains supply?

I've been told it is safe provided I follow the instructions carefully given on this website.

http://www.tnt-audio.com/clinica/mains_e.html

Many thanks for your help


Reply received:

No Richard you should not use co-axial satellite cable of the sort described to connect your audio equipment to the mains supply. This is unsafe practice. If your mains lead needs replacing you should it replace with the same type of lead that was supplied with the equipment. These can be purchased from high street electrical retailers.

If you are in any further doubt you can consult a qualified electrician for advice. Telephone numbers can be found in the yellow pages. Also we have a free booklet INDG231 Electrical Safety and You that can be downloaded from the HSE website which may be helpful.

Thank you for your enquiry.


No doubt you will continue to insist you are right Thorsten and the HSE are wrong. Either way be it on your conscience if someone has injured themselves as a result of your article; no matter what you think disclaimers written in red do not absolve you of this responsibility.
 
Hi,

You should ask WHY the practice is considered unsafe. The answer will be that the cable has not formally been approved for mains use.

Note that a lack of approval does not automatically imply unsuitability per se, merely that under the local electrical code the cable is not approved and certified for such use and hence is considered unsafe. Which is what I pointed out in my article and in my notes here.

You may wish to actually study the relevant standards and establish what sort of charateristics a Cable must meet in test to be certified. You will find, if you compare the requirements and the actual items that in terms ofbasic specification the cable could be certified for mains use, if anyone was prepared to pay for the approval process.

Which brings us back to the difference between DIY and Commercial and the disclaimer/warning etc. I am sure you are aware that ANY for of DIY electronics involving mains voltage are de-jure unsafe, as the builder would be required to gain full approval, unless of course he accept that he operates under his own risk.

If the warning bothers you and you feel unsure (as you obviously did) wrtiting (as you did) got you the standard advise for anything not officially approved to the relevant standards and/or by UL and/or according to CE, which is "it's unsafe". They will tell you the same about any Kit that involves wiring anything to the mains.

HOWEVER, their advise is strictly from the legal, not from the practical point of view, eg the fact that an item is not positively certified as meeting certain standards makes it unsafe, not the fact that it is not able to meet said standards, which was my point to start with.

In order to be able to reject my point that excluding formal approaval the cable is safe has not been addressed anywhere.

Ciao T
 
3DSonics said:
You may wish to actually study the relevant standards and establish what sort of charateristics a Cable must meet in test to be certified. You will find, if you compare the requirements and the actual items that in terms ofbasic specification the cable could be certified for mains use, if anyone was prepared to pay for the approval process.

Can you safely assume that the coaxial cable has the required insulation resistance?

Doubtful.

HOWEVER, their advise is strictly from the legal, not from the practical point of view, eg the fact that an item is not positively certified as meeting certain standards makes it unsafe, not the fact that it is not able to meet said standards, which was my point to start with.

Their main interest is safety, HSE always has been about that.
 
Hi,

wolfgang said:
Unpublished results have no meaning.

They have meaning to those to whome they are formally disemminated. Given that I have no iterrest to make the results available to the general public or wish to claim any relevance for them they have exactly the meaning they where meant to have, in my case as hands on, blind market research to suggest which of a range of items is best.

Had I wished to provide proof for the presence of differences between cables which would stand up to public scrutiny and would have significance and statistical power I would have approached the whole test and it's setup differently. As I did not and had no intention to publish I did not need to do so and hence I will not publish. No point to do so.

Ciao T
 
Hi,

penance said:
Can you safely assume that the coaxial cable has the required insulation resistance?

The cable is rated at 600V Isolation withstanding capacity.

Also (and this is something everyone seems to have missed) the cable that carries any mains voltage is actually FULLY ENCLOSED within the conductor that is used to cary the PEN connection, in other words, EVEN IF THE INSULATION BROKE DOWN (which it should not, based on rated voltages), there is no way this current could reach the outher insulation of the cable, as it would have to first "cross" the PEN (Earth) conductor. Electrical safety against electrical shock is inherent to the design, DESPITE a lack of formal safety approval, which automatically precludes for example the sale of such cables.

Ciao T
 
Most mains rated cables have 1000v insulation, but that is different to insulation resistance.
Isolation withstanding capacity, WTF is that???

Electrical safety is not inherent to the design, that also depends on fuse used and competance of the person who made it.
 


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