I Think We’ve Got A Lead…

January 14th, 2006 by Ben Goldacre in adverts, bad science, Hi-Fi, references, statistics, very basic science | 113 Comments »

Ben Goldacre
Saturday January 14, 2006
The Guardian

Ok, hold on to your girlfriends, because this time we get seriously geeky. Last week we were talking about hi-fi company Russ Andrews, and their £30 power cable, which they reckon will improve the sound of your stereo. It’s not a speaker cable, or a even a posh cable connecting your CD player to your amp. It’s a power cable, from the wall socket to your hi-fi, a bit like a kettle lead.

I expressed doubts that this would do much good. It turned out it was just the tip of the power lead iceberg. Russ Andrews have another one for £140. Stone Audio will sell you the “Super Mains 25 HARDLINK Polished Rhodium Plated UK 13A Supergrip Plug” for £150. And Cheshire Audio will sell you the “Experience Mains 32a – possibly the ultimate mains lead” for a modest £470, although they don’t make any specific claims about sound quality.

Now, interestingly, since last week, Russ Andrews have written in to explain how they believe their cable will filter out radio interference in the power supply, and so improve the sound of your stereo. Pay attention. They say their power cable has “a woven profile which takes advantage of the known effect of capacitive RFI cancellation of crossing wires, with the longer the cable and the more crossings in the weave, the more cancellation”.

Basically, what they are saying is, that the twists in the cable mean it acts like an electronic component called a capacitor. There is a geeky explanation for why this might filter out radio frequencies (to keep the pedants happy) and a simpler one (for those of you with a sex life).

The geeks’ explanation, which I honestly suggest you ignore, is this: a capacitor will allow higher frequencies, like radio frequencies, to pass through it, and go to ground. That is, it will “short them out”, take them off out of the cable, but will not affect the lower frequencies. I’d love to explain more about the fascinating subject of “capacitative reactance” to you on the news pages of a national newspaper, but I’d get the sack, and they’d probably give my job to the person who writes Ask Emma.

So here is a simpler explanation. You could think of this system as being a bit like suspension on a car: small, quick, one-inch-tall bumps will get filtered out by the springs in your suspension; but when you drive over a 200-yard-long one-inch-tall platform, your car does lift up into the air by an inch, while you’re driving over it.

The radio frequency interference can be thought of as very quick small bumps in the electricity supply, maybe a million little bumps every second, which a capacitor could filter out; but the mains supply also has big wide humps going up and down very slowly, only 50 times every second (the “50Hz” of the mains supply), which are necessary for your equipment to work, but which the capacitor won’t be able to affect, because they’re going up and down too slowly.

That’s the theory. But there are two problems with this. First, the people selling these cables are hardly the first people to notice that radio frequency interference in the mains power might mess up the sound of your hi-fi, so the power supply in your equipment will be chock full of all kinds of deliberate tricks to filter it out, and they are a lot better than a Boy Scout improvised capacitor made from a twisted bit of wire.

Then there is the most important issue. Forget the theory, however damning: can anyone hear a difference? I don’t mean, can you “hear” it when you know how much it costs, and you know you’re using it, and you know what you ought to hear.

No. What I want to know is: can you tell the difference between a £400 cable, a £30 cable, and a £1.50 cable, if you don’t know which one is being used at the time? That is a double blind trial. That is what I plan to do, and I need hi-fi reviewers and pedlars: so far I have two promises, but I need more. It will take an afternoon, but it will be worth it, and I’ll make sure it gets published somewhere. And if nobody volunteers I shall start choosing subjects myself. My email address is below.

· Send your bad science to bad.science@guardian.co.uk


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113 Responses



  1. Ben Goldacre said,

    January 17, 2006 at 11:31 pm

    I always want to hear about stupid Public Understanding of Science initiatives.

    Here or in private.

    In fact, I demand to be told stupid Public Understanding of Science initiative stories.

  2. David said,

    January 18, 2006 at 1:02 am

    Has anyone here heard of EMC(electromagnetic compatibility) testing? There are standards for testing products which said products are required to meet to be sold in most EU countries. These are EN and ISO standards. They cover a broad range of topics, from humidity and temperature cycling, HALT, to ESD requirements.

    Specifically, I would like to mention 2 standards. EN 61000-4-3 and EN 61000-4-6.

    4-6 is a conducted immunity/susceptibility standard. Essentially, any cable greater than 3 meters is required to have RF noise of the frequencies 150kHz to 80 Mhz injected onto the cable. This includes signal cables and mains cables. Any degredation in performance will result in a failure.

    4-3 is a radiated immunity/susceptibility standard. RF between 80 MHz and 1000 MHz are radiated onto the device and cables. Again, any degredation in performance is considered a failure.

    Most commercial electronics should have already been tested to these standards to be sold in the EU. In the US, there is no specific requirement for immunity, only emissions.

  3. Andy said,

    January 18, 2006 at 6:11 am

    David,

    I agree with your comments that all HiFi equipment on sale will have passed the CE mark testing required to sell electronic equipment within the EU. I would even expect the vast majority of equipment in the US to have passed the test; most equipment is designed for the global market these days. As I commented on last week’s story, I’ve done enough of this testing myself in the past.

    However there are two problems with the testing being applicable in this situation: Firstly the field strengths involved in the radiated immunity are 3 V/m, hardly a strenuous test and secondly the pass/fail requirement is that the device continues to operate, a slight distortion or demodulation of the radiated noise would not result in a fail. Test labs are not the best acoustic environment, people probably wouldn’t even notice unless there was a gross distortion to the sound.
    In previous conversations with the engineers at several labs I’ve asked if they see many failures on these tests, they have often tested several products a week for years and never seen a single failure on the radiated immunity test.
    Now some of the automotive and military specifications which call for fields one or two orders of magnitude stronger are a different matter but no one is going to test a HiFi to those standards, few test labs can even reach a field strength that high.

    On the conducted emissions/immunity testing the same applies; a mild distortion is not going to result in a product failing, as long as you can still hear the music the equipment is still functioning correctly and passes. Plus if you were to check you would find that just about all cables supplied with equipment in the EU are 2.9 meters or less, it’s easier and cheaper than running the tests.

    However as I commented previously such a test lab would be the ideal place to test out these cables, they would have the equipment needed to perform some calibrated and highly sensitive measurements of the claimed effect of a £40 mains cable. If you happen to know a UK lab which is willing to donate half a day or a days worth of time and equipment for these tests I’m sure Ben would be very happy to hear about it 😉

  4. Jon said,

    January 18, 2006 at 12:31 pm

    Check out these – www.virtualdynamics.ca/products/ASR/ – starting price $2k for the ‘platinum’ version… They provide a great report which “measures and verifies the influence of the Resonators” as well (the fact they spell ‘repport’ incorrectly on the first page is a good marker of the quality of the rest of the document…) – www.virtualdynamics.ca/lit/Acoustic%20V0%201.pdf

    Makes a £40 mains cable seem a great investment 😉

  5. Dunc said,

    January 18, 2006 at 12:46 pm

    [blockquote]Even low-end separates systems tend to have half-decent PSUs and filtering. And no-one’s buying a £40 cable for an £90 integrated hi-fi (assuming the cable wasn’t hard-wired anyway).

    […]

    I think it’s safe to assume that someone thinking of buying a £40 power cable, has spent at least £200 on the amplifier into which they intend to plug it.[/blockquote]

    We have different ideas of what “low-end” means… 😉 A £200 amp will probably have a construction cost of less than £50, which I’m not convinced is enough to build you a decent PSU.

    Assuming that something is well made because you paid a decent amount for it is kinda like assuming science journalism is accurate because it’s in a “quality” paper. 😉 Most commercially-produced hi-fi equipment is pants, IMHO.

  6. GWO said,

    January 18, 2006 at 12:52 pm

    A £200 amp will probably have a construction cost of less than £50, which I’m not convinced is enough to build you a decent PSU.

    It seems we have different ideas of what “integrated” means, too.

  7. Delster said,

    January 18, 2006 at 1:58 pm

    Thanks Andy, at least we now know why the cables are always just that little bit too b*&%*y short

    this is an interesting article on freezing Cd’s and audio tapes to improve the sound quality www.belt.demon.co.uk/tfs.html

    it even claims that if you put a previously frozen tape into a machine and then play the CD then the CD will sound better….. anybody feel like a bit of bashing on that one?? or would that be too easy?

  8. David said,

    January 18, 2006 at 3:36 pm

    Andy,

    I can’t really disagree with any of the points you stated. Being an engineer at one of said testing facilities, you are spot on with most of it. The acoustics are not very good in most of our test areas. 3 V/m for radiated, and 3 V for conducted are not very high test levels.

    Two things I will take issue with though; namely, during EN testing radiated immunity testing has the second highest failure rate of any tests we run(behind ESD). We may not see a failure every week, but they are not rare. Also, conducted immunity is always tested for mains cables. The thinking is that since you’re plugging into a wall outlet with miles of cabling behind it, that constitutes the 3 meter requirement.

    I would be glad to help in testing out these claims, but I don’t think Ben wants to fly to Minnesota(plus I’ve been working 12 hour days the past few weeks).

  9. JohnHankinson said,

    January 19, 2006 at 12:22 pm

    All the techniques for improving CD quality (pen, freezing, stickers and other bullsh1t) are easily disproved, even without a listening test. Its a digital medium, so all you do is look at this bits as they come off the disk (16-bit PCM @ 44.1KHz so a 88.2KBps stream) and compare against the original bit stream.

    In fact this is common practice when mastering from one media to another in any audio mastering facility so that you are sure there are no digital errors during transfer.

    To cut a long story short, all these CD enhancement tricks are complete balls – any anyone with any basic knowledge of digital audio should be able to see this.

  10. Ben Goldacre said,

    January 19, 2006 at 12:36 pm

    am i alone in thinking that gold plated optical cables are properly, PROPERLY ridiculous?

  11. JohnHankinson said,

    January 19, 2006 at 5:20 pm

    Ben, you are not alone – they are ridiculous, but on the other hand they are very shiny and quite amusing – so not all bad then.

    Of course I could say, “the Quantium coherence effect in certain highly polished rare metallic elements is such that the refraction index of an optical medium can be greatly enhanced when the metallic element is present, especially where the medium interfaces with air. Hence gold plating an optical cable is not an invalid concept.”

    I would be talking bollocks, but that doesn’t stop me saying does it?

  12. Andy said,

    January 19, 2006 at 5:48 pm

    Gold plated optical cables make about as much sense as the sales pitch that a gold plated USB cable to you printer will result in sharper photo prints.
    Why let logic get in the way of a larger profit margin?

  13. Fontwell said,

    January 19, 2006 at 5:50 pm

    “the Quantium coherence effect …”

    One indicator that a field is completely without merit is when you cannot tell the difference between a pastiche and the real thing.

  14. JohnHankinson said,

    January 19, 2006 at 8:38 pm

    “One indicator that a field is completely without merit is when you cannot tell the difference between a pastiche and the real thing.”

    The irony being that if you find yourself in this position, you wouldn’t know it was a pastiche!

    Is there such a thing as a “cornish pastiche”? I quite like the idea of that….

  15. Fontwell said,

    January 19, 2006 at 9:16 pm

    “The irony being that if you find yourself in this position, you wouldn’t know it was a pastiche!”

    Exactly. I bet that if you put your Quantium Coherence Effect post in the right forum it would be taken seriously. Which gives me an idea…

  16. Ben Goldacre said,

    January 19, 2006 at 9:33 pm

    go, baby, go…

  17. Squander Two said,

    January 20, 2006 at 10:03 am

    That Hi-fi Wigwam forum is hilarious. You write an article suggesting that a scientific claim be tested, and they accuse you of rubbishing the claim without first testing it. I like the bit, too, where they say that your article was poorly researched because you only suggested testing a manufacturer’s claim about one of their products and failed to mention every single thing that manufacturer produces. I really hope your tests prove them wrong, just so I can enjoy reading their insane reactions.

    One major factor that hi-fi fanatics never take into account is that most record producers deliberately test their recordings on cheap crappy all-in-one players with tinny speakers to make sure that the finished product sounds good no matter what you listen to it on. Yes, high-end hi-fis will reveal subtleties in the sound, but not important ones: if the musicians like a particular detail of the sound, they make damn sure that it’s brought out in the mix so that it can be heard on cheap crap.

  18. JohnHankinson said,

    January 20, 2006 at 4:05 pm

    Its funny because I was chatting to my dad about this, and he posed me a simple question:

    “What do you think sound engineers in a studio do when a cable fails or a length of cabling is needed?”

    Now i’m sure this isn’t true all the time, but I know from my IT experience that when a network cable breaks, you don’t pop down the shops for a new one – you simply get out a cable spool, two RJ-45 connectors and a crimping tool and make one yourself. Its cheaper and quicker and you get a decent, working cable out of it.

    According to my dad (who should know), this practice is also standard in recording studios and mastering facilities. So if the cable used there is cheap but solid home-made stuff, why on earth would using an audiophile interconnect help on playing back the shop bought product.

    And as for power leads, you should see the big cardboard box in the cupboard they have full of old kettle leads. I can tell you none of them are anything but standard cables – some may even have come from kettles.

  19. Andy said,

    January 20, 2006 at 5:23 pm

    Now I understand where we are all going wrong.
    Apparently blind tests hide differences which you can hear if you know what you are listening to.

    “But when you have taken part in a number of these blind tests and experienced how two amplifiers you know from personal experience to sound extremely different can still fail to be identified under blind conditions, then perhaps an alternative hypothesis is called for: that the very procedure of a blind listening test can conceal small but real subjective differences.”
    www.hometheaterhifi.com/volume_11_4/feature-article-blind-test-power-cords-12-2004.html

  20. Tom P said,

    January 21, 2006 at 8:27 am

    “real subjective differences”

    Gentlemen, start your epistemologists.

  21. Nick P said,

    January 21, 2006 at 2:38 pm

    My connection with the hi-fi trade is, firstly, as a customer; secondly, I wrote a computer system for managing a hi-fi shop that’s currently in use in a number of premises.

    I’m very ignorant about electronics, and analogue circuit design in particular.

    I _have_ had experiences of mains light switches interfering with the hi-fi, but that was with a particular pre-amplifier that had been modified by the manufacturer to incorporate a moving-coil phono stage specifically designed for a Linn Karma cartridge. Was it mains interference getting through the power supply of the pre-amplifier? Or was it mains interference with the new cards? I’d go for the latter, since the only change had been the new card.

    … which brings me on to my thoughts on the forthcoming trial:

    1. I briefly met, in the 80s, Linn Products’ amplifier designer. He averred that one of the most important requirement for his amplifiers (Linn had recently launched its first) was a really good power supply. If this is actually the case, then, if there really _is_ a power-lead effect, then it is more likely to be revealed by poorly-designed products. So, perhaps the equipment selected in the trial should come from a range of manufacturers.

    2. Use a record-player as a source; use one with a moving-coil cartridge. These cartridges are low output – from memory, 0.5mV. If the power cable succeeds/fails to filter mains interference, then one might expect this interference to revel itself in the component that’s dealing with the weakest signal i.e. the moving-coil phono stage in the preamplifier.

    3. Twenty-five to thirty years ago, when buying a hi-fi, you bought the best speakers you could, and bought source & amplifier based on the supplier’s “performance” measurements. Witihin 10 years, then then-heresy that you should actually _listen_ to a system that was intended to play music had become mainstream. Again, at that time, bell-wire was typically used for the speakers, whereas no-one today would really argue against using quite beefy stuff. Perhaps 15 years ago, various hi-fi nuts started claiming that a hi-fi could sound different depending on which way around you had the interconnects; the claim was resoundingly pooh-poohed by pseudo-scientists (who claimed to be scientists) because there existed no theory to explain the claimed observation. Now, it’s quite likely that cables supplied by the manufacturer (ie not after-market add-ons) will be marked to show which end should be plugged in to the source and which in to the destination.

    4. Don’t bother recruiting hi-fi journalists; generally speaking, their ears aren’t much use ‘cos their heads are stuck up their a**e (… actually, _do_ recruit one or two; the humiliation should be fun!). MUCH better to recruit test subjects at random off the street; my experience of having sat in at demonstrations (not as buyer or seller, but “tourist”) is that the vast majority of people can quite easily identify differences in the sound from different pieces of kit. ‘Course, whether they _value_ the differences is entirely different.

    N
    (feeling that he might have just set himself up for a monster flame!)

  22. RS said,

    January 21, 2006 at 2:48 pm

    Andy, that was quality, my favourite being:

    “Has no one heard anything about Quantum Physics, which questions the existence of an absolute objective reality?”

  23. Andrew Rose said,

    January 22, 2006 at 7:41 am

    At the risk of repeating what has already been written here by others I just wanted to contribute a little to this debate. I’m not an ‘audiophile’ – rather someone who has worked for many years as a sound engineer – both at the most senior level at the BBC and more recently in audio remastering and restoration.

    What I do a lot of these days is the restoration of vintage audio – although a newcomer to this particular corner of the music industry my work won three awards as recordings of the year in 2005.

    This kind of work requires very a precise listening environment in order to tease the finest nuances out of recordings made using often relatively primitive equipment. Being able not only to hear every defect in the original but also precisely what happens when I try to treat it is very important. As far as my audio equipment is concerned there are two crucial points – the replay from disc (vinyl or 78s) and the monitoring equipment.

    In both of these areas it is clear that investment pays off. Getting good sound out of analogue grooves is tricky (which is why the audiophiles like vinyl – plenty of opportunity for tweaking and spending money there). But once it’s done and digitised for restoration, it’s the listening equipment that really matters.

    What this means is good loudspeakers. The difference between a pair of £550 hi-fi speakers and my ex-BBC studio monitors is huge – the resolution of the latter and the abilily to hear the very smallest differences and finest nuances in sound is truly incredible. (These speakers cost the BBC the current-day equivilent of about £10,000 per pair when they introduced them in the late 80’s.)

    So, listening on these ‘wonder-speakers’ (each with its own dedicated Quad power amp), with ‘trained’ ears (I can just about still detect sine waves up to 20kHz), and working at very fine resolution, I ought to be able to hear if something makes a difference to the sound quality I’m hearing, whether I’m listening to vintage material or the most modern, high-resolution sound.

    So, at the risk of blowing my credibility as a sound engineer, what differences do I hear as I switch leads, cables and so on? Absolutely nothing. Zilch. The whole thing is a massive con. I think most people working in my profession would privately agree – some would happily go on the record. Most of us find the kind of nonsense spouted at the more extreme end of the audiophile community hilarious – but even at the ‘sensible’ end there’s a whole load of barmy claptrap spoken and written.

    So good luck with this one, Ben. If I didn’t live in France I’d be happy to come along and lend a pair of ‘expert’ ears to your trial – but I guess the Guardian’s expense account might just rule me out! 😉

  24. Rwdls Nwdls » Gwyddoniaeth Gwael said,

    January 22, 2006 at 3:57 pm

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  25. Robert Carnegie said,

    January 23, 2006 at 3:03 pm

    Re speaker wire polarity, surely if one speaker pushes as the other one pulls it’s going to make a difference… and I believe I once produced an odd effect on those lines by putting a monophonic signal through opposite-polarity speakers.

    Re geeks, the butt in this surely is not science otaku but hi-fi snobs, and they so have it coming to them.

    Re interference, I would like to know if a DECT phone must be expected to make any sound reproduction kit near it go bz bz bz bz bz bz bz bz, about 3 pulses per second. I also own a couple of dirt cheap cassette players which go bzzzzzzzzzzzzzz when used within about 50 metres of local cell phone masts. Come to think, I could probably listen to that on the bus home with my eyes closed and still know when to get off. But a real GPS solution would probably be better.

  26. Andrew Rose said,

    January 23, 2006 at 6:43 pm

    Robert – you’re right about speaker polarity in that it’s certainly important to have speakers wired in phase – otherwise all stereo spacial imaging is lost. This however has nothing to do with the alleged directionality of some hi-fi speaker cables – rather it just means you need to connect positive speaker terminals to positive amp terminals and negative speaker terminals to negative amp terminals.

    Some in the audiophile community claim to hear a difference in the actual direction of the wire (not the polarity). This is why some cables come with arrows on them – these indicate the cable direction from amp to speaker. Despite what would appear to be the obvious fact that we’re dealing here with an alternating current which constantly moves in both directions, some audiophiles do think this makes an audible difference. I’m afraid I think it’s just another load of old nonsense – but what cable manufacturer is going to risk losing sales by not printing arrows on their leads?

  27. Nick P said,

    January 23, 2006 at 7:29 pm

    “… but what cable manufacturer is going to risk losing sales by not printing arrows on their leads?”

    Which is why I think it interesting that some manufacturers include cables with the kit that are marked in exactly that way, something which the punter will only find out long after they’ve taken the plunge… Sure, after-sales companies will want to make everything seem as totally hi-tech & utterly brilliant, but for suchlike items sealed in a box & “given” away with the product? Suggests that _some_ think there’s an effect.

    I’m interested, Robert, in what you say about your monitors & their amplifiers being the most important item for your work. How does the source affect things? Some would claim that, if you ain’t got it off the record or CD in the first place, the speakers ain’t gonna add it back, but it’d seem that your experience is different?

    N

  28. JohnHankinson said,

    January 24, 2006 at 1:53 pm

    Nick P:

    “…but for suchlike items sealed in a box & “given” away with the product? Suggests that _some_ think there’s an effect.”

    or the more simple explanation is that they source their cables from a cabling manufacturer that happens to mark the ends of the cable. For economy’s sake a hi-fi component manufacturer may well not be a cable manufacturer and the fact that a marked cable is in the box will be related to the supplier of that cable more than the hi-fi manufacturer.

    “I’m interested, Robert, in what you say about your monitors & their amplifiers being the most important item for your work. How does the source affect things? Some would claim that, if you ain’t got it off the record or CD in the first place, the speakers ain’t gonna add it back, but it’d seem that your experience is different?”

    The speakers have the most important job in a hi-fi, they convert electrical signals into mechanical movement and into longtiudinal waves in the air. This is by far the most complex task in sound reproduction and so all sorts of variations in reproduction can creep in here depending of freq. response of the various cones, horns etc., contact with the ground (for bass reproduction), volume etc.

    The amps that Robert refers to are specifically power amps. Their job is not to change the sound in any way but to drive the speakers. In this sense, what matters about power amps is their power rating (given in Watts – usually Root Mean Squared and Peak). Insufficient power in the amp will mean the drivers in the speakers don’t provide the volume they should (and excessive power does very scary things indeed!). The SNR is also important since you don’t want excessive noise introduced when cranking it up.

    The point is that in these days of digital audio and high-quality mass manufactured audio components (like D/As and CD pickups) the source and preamp components themselves rarely make any difference to the sound as it goes through. Admittedly, you do get faulty components, occasionally inferior components and also you can get components that are manually set (like EQ and bassboosts) that will change the sound – but putting these issues aside, most system components will not cause a perceptible difference to the listener.

    Speakers on the other hand do. Try listening to something through your internal PC speaker vs. some desktop speakers via the line out vs. a basic hi-fi via the line out. for example.

    As for mains cables…

    To really expose the fraud with these things, look at the facts that the audiophiles claim a CD player connecting via a digital out can be improved by using them. This is complete tosh – and if it were true, IBM wouldn’t supply servers with basic kettle leads that’s for sure…

  29. Don Cox said,

    January 25, 2006 at 4:08 pm

    “Inductors could be used to make filters a lot more” – some amplifier manufacturers do use inductors in the power supplies. It costs more.

    “Admittedly, you do get faulty components, occasionally inferior components and also you can get components that are manually set (like EQ and bassboosts) that will change the sound – but putting these issues aside, most system components will not cause a perceptible difference to the listener.”

    The analog output stages of most components are IMO poorly designed, to keep the price down. The output impedance tends to be too high for the input impedance of the power amp. The practical result is that frequency response narrows as the voltage goes up. This gives a “hard” sound.

    Another thing that varies (audibly) is the digital-to-analog converting chips. These seem to be improving as the years go by.

    A couple of people said that speakers make the most difference. They are important, but in my experience the listening room makes even more difference.

  30. JohnHankinson said,

    January 25, 2006 at 5:53 pm

    Don – point accepted RE: the listening room – i was assuming this not to be part of ‘the system’ – but you are correct that it has the single biggest effect!

    As for your comments RE: analog stages of amps and D/As, i’d disagree, but I’d guess neither of us have any objective evidence either way!

    D/As these days are mass produced at such high quality that I have serious doubts about the effect they have on sound (barring faults). As for analog components, I’m sure you’re correct in some cases, but it would be interesting to see if you could tell the difference between an out of the box component and one with an ‘improved’ analog stage.

  31. Paul Snow said,

    January 26, 2006 at 10:31 am

    Hi Folks,

    Feast on this for your entertainment:

    www.cardas.com/content.php?area=insights&content_id=7&pagestring=Golden+Section+Stereo+Magic

    Best wishes,

    Paul

  32. John L said,

    January 26, 2006 at 2:29 pm

    “this is an interesting article on freezing Cd’s and audio tapes to improve the sound quality www.belt.demon.co.uk/tfs.html

    Ah I see the name Peter Belt in this wonderful piece.

    If memory serves back in the dark ages someone called Peter Belt sold magic stickers that made your Hi Fi better by controlling gravity waves (without aid of work done).

  33. Ben Goldacre said,

    January 27, 2006 at 12:51 am

    how about this:

    www.etsy.com/view_item_sold_anon.php?listing_id=69369&transaction_id=16776

  34. Andrew Rose said,

    January 27, 2006 at 3:44 pm

    Why are leads given away with arrows? Well those with longer memories will remember the pasting that some hi–fi manufacturers got a few years back in the hi-fi press for hard-wiring their mains leads into their equipment, rather than supplying a ‘figure of eight’ plug – the theory being that the electricity “polarity” (we are of course talking AC here) made an audible difference to the overall sound. I don’t suppose they really want to go down that same route again for the sake of a few pointless arrows.

    BTW has anyone got any information on what precise characteristic of the wire used in these cables is that gives it ‘directionality’ – whether in an AC or DC environment?

  35. Andrew Rose said,

    January 28, 2006 at 6:35 am

    Interesting article on the subject of power leads (part of a larger series which takes in a number of other points raised here, including ‘directional’ cables):

    sound.westhost.com/cables-p4.htm

  36. Nick P said,

    January 28, 2006 at 2:36 pm

    “Interesting article on the subject of power leads (part of a larger series which takes in a number of other points raised here, including ‘directional’ cables)”

    … but a remarkably un-scientific one…

    Yes, I _did_ say UNscientific.

    His (knowldege of ) theory cannot explain any possible effect, and his measuring instruments also can measure no effect, but at no point has he actually set out to disprove the claims by experiment.

    “BTW has anyone got any information on what precise characteristic of the wire used in these cables is that gives it ‘directionality’ – whether in an AC or DC environment?”

    The only thing I’ve come across in this line doesn’t, for me, offer a particularly satisfactory explanation since we _are_ talking about an AC signal. The idea is that strands in a cable start out as a billet that’s progressively taken down to its finished size by being drawn through a succession of dies. In metals, less soluble phases (more resitive?) tend to form at grain boundaries, and the grain boundaries are deformed by the drawing process such that they effectively form arrows pointing in the drawing direction… Regardless of whether this _is_ the explanation for the claimed effect, it’s probably accurate in its suggestion that strands of copper are not of the same structure/form in all directions.

    N

  37. Howard said,

    January 28, 2006 at 8:34 pm

    If I don’t wire up the speakers the correct way round to the amp (+ to + etc, not that my 20 year old speakers have any polarity indicators on the wires that stick out of them!) then the amp cuts out about half-way round the volume dial 😉 Any comments?

  38. Derek said,

    February 3, 2006 at 10:44 pm

    Back in the early 70’s my dad bought an amp he’d heard good reviews of, after a couple of days he took the caseing off looked at the circuit boards and decided to take it back and swap it for another make.
    His reason was, it wasnt filtering out mains “shash and pops” properly.
    He was an an electical engineer.
    6 months ago a good friend and collegue was looking at a brochure for one of these cables and was about to buy one.
    I thought he was wasting his money and phoned my dad, remembering the 70’s.
    His verdict……….”i’ve never had a problem with that since then, the capacitors in that amp were for cheap radios. He’s just wasting his money”
    I agree. Waste of money.

  39. Tim Anthony said,

    February 4, 2006 at 9:37 am

    I just put a 10microfarad electolytic capacitor across the power terminals of my extremely expensive octophonic amplifier, and it exploded. Now I’m deaf. Couldn’t one of you have told me not to do that?

  40. ben w said,

    February 5, 2006 at 11:38 pm

    I would have done but I can’t see into the future because I’m blind

  41. Ian Leslie said,

    February 6, 2006 at 4:01 pm

    One or two of these posts have hit on the key point in hi-fi today: the interface(s) between modulated voltage and air pressure are what make differences – except perhaps at the very cheapest end, ALL electronics meet the highest requirements of the human ear’s power of discrimination.

    I use a pretty expensive pick-up (I still sometimes listen to vinyl still) and the QUAD ESL-63 electrostatic speakers but in between, just good not audiophile gear. I am perfectly satisfied with a DVD-player that cost £40 and also plays my CDs, including ones recorded by engineers at the very top of the profession, to my entire satisfaction.

    Not worth mentioning the compromises involved in designing a gramophone pickup, since they are now obsolescent anyway, but I will mention that ALL moving-coil cone speakers and combinations thereof are examples of constantly varying tweaks to make something work well despite obvious shortcomings (cf. motorcycle teledcopic forks!). These include the fundamentally incompatible requirements of rigidity and low mass; interefernce between sound waves leaving different parts of the cone; intermodulation of High-frequency (short) waves by low-frequency (longer) waves as the cone moves back-and-forth; the essentially resonant nature (both electrical and mechanical) of the cone-and-coil-and-suspension combination; etc.

    The electrostatic system sidesteps these difficulties not by tweaking but by a fundamentally different approach and IMHO (despite MANY sessions at hi-fi demos) is where the whole effort of hi-fi development should go, because it is possible that development on Peter Walker’s work (Peter Walker having now retired) could produce even better STEREO rendition – though not, I reckon, better basic sound.

    But it is much easier to make a lot of money by constantly tweaking the moving-coil system so as to produce “new,” “breakthrough” designs every ten minutes or so requiring much audiophile expenditure; and easiest of all, yes of course, by selling a bit of cable with magic properties for magic prices.

  42. mikey said,

    February 7, 2006 at 9:54 am

    Make sure that when you do your experiment you do it on a domestic mains supply and not using “tech mains” in some audio facility somewhere. Otherwise there may not be anything to filter out in the first place? Does tech mains goes through a transformer to isolate it from noise in the same way as balanced audio transformers?
    Also maybe someone could be in a sound proof booth in the next room making a cup of tea & watching Eastenders or flicking lightswitches on & off, or using a PC with a dodgy power supply fan?

    The science can be first class but the experiment design has to be right.

  43. davewhit2 said,

    February 7, 2006 at 3:48 pm

    talk about moving the goal posts, you write an item on £30 leads being expensive

    a few of us pointed out how £30 is cheap, now you claim

    “from £30 to a whopping £1,800” you moving to the Sun soon ?

  44. Paul J said,

    February 7, 2006 at 4:28 pm

    Not all of us audiophools are mains-lead junkies, witness the horror: i51.photobucket.com/albums/f363/biscuitbarrel/e61f2d75.jpg

    Remarkably the perp still lives…

    FWLIW I use fire-alarm power cable for (almost) my entire system – it has a heavy aluminum shield preventing pick-up and radiation of local EMI (and this was a problem), and best of all it came out a skip – left-over from a building project. So now the hifi can play-on while the house burns down…

    The only exception is one of the “cheapest” (by audiophool standards) mains leads I’ve used (and I’ve tried dozens) – this has separate coaxial solid silver conductors for both live and neutral with the earth carried by the screens (don’t worry it’s thoroughly tested and very well insulated!). Unconventional, but very effective I find.

    In spite of having been involved in some inconclusive double blind tests of power cables, and also being fully aware of the likely psychosomatic influences, I don’t dissmiss the possibility that this odd cable geometry has some real benefit – perhaps in isolating live and neutral legs of this part of the circuit from each other – after-all, most complex electronics not only _suffer from_ mains interference, they also contribute to it…

    As you can see I’m flailing-around for an explanation, but then I’m a geologist, not a physicist. So, despite having put good money the way of cable vendors, I remain on the fence on this one – the DBT I was involved in suffered from having far too few test subjects (3) – hardly statistically significant, so I think (Ben) you should throw this open to any interested party to participate, I find dealers and vendors PARTICULARLY reluctant to get involved – perhaps rather tellingly… I’ll certainly put my ears where my mouth is, notwithstanding anatomical considerations…

    cheers, Paul

  45. Johnny B Goode said,

    February 7, 2006 at 4:39 pm

    Stand up all you above that own a hi-fi system.

    Stand up all those people above that have actually bought or tried an aftermarket power cord.

    Thought so.

    All I have read above is jingoistic whining by by a bunch of pre-teen schoolchildren who have just discovered Father Christmas does not exist. The worst naysayers of all are the alleged “techie” types that believe implicity their knowledge is totally infallible, but it wasn’t that long ago I recall that conventional current theory proved to be entirely wrong and all the text books had to be re-written smartish.

    I would have given some sort of credibility to Ben Goldman’s research into the subject if he abandoned his News of the World style of “fearless expose” purely for their sensationalist shock/horror tactics and kept an open mind on the subject. As it is, I cannot forsee ANY cable manufacturer/dealer coming forward when there is already such overt and deeply negative bias towards the subject. I don’t blame them, but this seems to be translated by the feeble minded into “avoiding the challenge”. Grow up please. I’m surprised that Russ Andrews didn’t say “p*ss *ff”, but bless him, he’s probably read garbage like this countless many times before.

    What these aftermarket power cords do has very little to do with “rejecting RFI” by the way, so take that statement with a pinch of salt. It does have something to do with the conductor material and impedance of the wire but that isn’t the whole story either.

  46. davewhit2 said,

    February 7, 2006 at 6:05 pm

    Ian Leslie said,
    February 6, 2006 at 4:01 pm

    said ” including ones recorded by engineers at the very top of the profession, to my entire satisfaction”

    easily pleased

    you then said

    “(Peter Walker having now retired) ”

    Died last year

  47. davewhit2 said,

    February 8, 2006 at 12:01 pm

    why did you remove my post from www.the-scientist.com/article/display/18831/

    muckraker they called you

  48. big said,

    February 14, 2006 at 5:58 pm

    I’m also an ex-BBC sound engineer, but with an interest in hifi, which I found to be quite rare – most thought it was like a busman’s holiday!
    Anyway, my gear is amplified through a particularly large and bruising power amp (pure Canadian muscle!). And my mains lead is the one that came with it.
    I also have an expensive mains lead that was given as a sweetener for a cd player (£200 worth of lead..).
    Having tried the quite beefy OE lead, and the expensive but similarly beefy HiFi lead, I couldn’t tell the difference. Using them on my cdp, and phono stage also showed no difference to my, undoubtedly ageing, ears.
    So the conclusion I came to was that so long as the lead was electrically sufficient to convey the power needed, then no difference could be noted by simply spending much more money on a shiny one with lovely logos…
    BTW, my kettle uses around 2kW, about as much as my amp at absolute full destroy-the-foundations power..

  49. Stumpy Pepys said,

    February 15, 2006 at 12:15 am

    For a long time, Richer Sounds — a company I generally have a lot of time for — was instructing customers to spend ten per cent of the purchase price of hi-fi equipment on cables on interconnects.

    I would have complained, except that it would have cost me the price of a stamp. However, having visited the site again, this advice has disappeared! Yay!

  50. Nick P said,

    February 19, 2006 at 11:38 am

    Sometime recently, Ben’s column in the Guardian (if I remember it rightly) outlined the proposed methodology for the trial.

    My understanding is that he proposes to make audio files available for download: one recorded from equipment using the default mains-lead, and one using the lead under trial.

    _IF_ I have understood him correctly, & recalled correctly, then… (and, if I’ve understood wrongly, naturally the following hardly holds trus, except perhaps the last paragraph, beggining with “i.e. Ben…”):

    This is extremely poor methodology; a fundamental principle of any trial involving measurement is that the measuring instrument needs to be capable of detecting the expected effect. If the instrument is not accurate enough, or not precise enough, _NO_ concludion can be drawn about whether the hypothesis is upheld or not.

    So: for Ben’s methodology to be capable of testing the experimental hypothesis (“the claims of exotic mains-lead vendors/manufacturers are valid”), he _first_ needs to demonstrate that the audio files he intends to distribute for a vox pop are capable of reproducing know effects that are of similar scale to those claimed for the exotic mains-leads. This might, for example, involve distributing two “calibration” recordings. To take an example from my own experience where I know their’s a readily-detectable effect, make recording 1 from a vinyl LP played on a Linn Sondek LP12 with Ekos pickup arm & Arkiv cartridge, and recording 2 from the same turntable combination, but with a known lower-performance arm/cartridge combination (dunno if the products are still around, but Linn’s Basik LVV arm and A&R Cambridge C77 cartridge were really good performers for the money at the budget end).

    i.e. Ben: how do you propose to calibrate your detection equipment? How do you propose to ensure that a negative is a true negative and not as a consequence of not using suffiently-good detectors? And, how do you propose to address, in the experiment’s design, your bias in favour of the null hypothesis?

    N
    (all of whose mains leads & interconnects came from the same box as the bits of kit, speaker cables excepted, which are speaker manufacturer’s standard cable & terminators.)