Some HDMI cables are graded by the HDMI specification they have been tested to, the latest specification HDMI 1.3a calls for cables to be graded as Cat 1 or Cat 2 depending upon the data rate they can support. HDMI 1.3 Cat 2 cables are just appearing and will support resolutions of 1440p and 2160p. Most users require nothing more than an HDMI 1.1 cable and many HDMI 1.1 and 1.2 cables (especially shorter lengths) would be graded 1.3 cat 1 had they been tested to the specification. There is no difference in pin wiring between HDMI cable versions, the HDMI changes refer to feature changes that are implemented in the video equipment.

its a bit like USB cables in a computer. Version 1.0 in a computer is fast enough for most people, but its good to have the extra bandwith and you would want to future proof yourself and get version 2.0 in USB cable.

if its roughly the same price get the 1.3 CAT 2 cable

http://www.emc.york.ac.uk/cost286/JT...20on%20BPL.doc

you could take a look at this report for a generator, which would possibly give you more stable flow of electric than the mains..................... or worse flow; but as emergency generators are up and down the country for buildings etc they might not be worse.

The person who wrote that is either unduly pessimistic about the quality of the HDMI receiver chips in Toshiba's TVs, or else ignorant of what the HDMI licensing authority themselves have to say on the subject:


The author of the Toshiba manual seems to have taken the most pessimistic assessment of the capability of category 1 cables and applied it to category 2 cables. There appears to be no other basis for the 1.8 metre limitation, and the claim about backward incompatibility is simply wrong.

yes I have listened too the Linn equipment firstly WITH then WITHOUT and then WITH the mains conditioner on.

It definetly works with audio, albeit high end stuff.

I can only tell you what I heard. I have no idea if it gives you a better picture on a telly though. I am a bit sceptical with that one , to be honest ; but I wouldnt discount it until I had seen a demonstration.

bell wire is simply a term for the speaker cable that is thrown in with a Hi-Fi to make the sound work.

so I take it you have no RGB/SCART or HDMI equipment and watch everything through good old RF cable ?

it does the job doesnt it?

You are aware of the placebo effect, right?


Really? I've never had speaker cable "thrown in" with any speakers I've ever bought. I supply my own. And bell wire has a rather specific meaning, because it's very thin gauge cable that you can buy in DIY stores to connect (wait for it...) doorbells. I've only ever seen similar cable used in horrid "music centre" type systems. Certainly nothing that deserves the term Hi-Fi.


On the contrary, I use a combination of RGB, component video and HDMI (with s-video in one legacy application).

That's because I understand video formats and the reasons why some are better than others. There are sound technical reasons underpinning these choices, rather than the pseudo-mystical mumbo-jumbo that attaches to the sort of "audiophile" trickery I've been criticising in this thread.

yes i am well aware of the placebo effect.


and with a shielded scart and a non shielded scart you can see the difference

different matter with hearing. Just because you cant hear and see the sound, then your brain may not take in the difference.

If all this gadgetry is a load of rubbish, then why not stick to ' bell wire ' instead of supplying your own?

I think some people on this thread could benefit from reading a decent GCSE Physics textbook - there's a lot of misunderstanding and assumption about how electrical signals work in the digital domain.

Analogue signals obviously benefit from a good quality signal path, but as has been stated so many times a digital signal is correct or incorrect with no half-measures - certainly none which could have a positive effect on picture or sound quality!

Still, it's nice to know that the placebo effect is alive and well. Keeps the homeopaths in business if nothing else!

There are good scientific reasons why a thick wire with low resistance is better than a thin bell wire with high resistance.

Better quality scarts can make a difference but only up to a point and once that point is reached there will be no perceivable difference.

I can't say whether a mains conditioner would make a difference to a Linn turntable or not as I have no idea what the internal circuitry is - I find it unlikely unless the mains was very bad but not impossible. Linn have a good reputation so I would be quite surprised if they designed something that couldn't handle a slightly noisy mains. (Any "mains conditioner" shouldn't cost more than about £20).

People will believe what they want to believe, the placebo affect is massive and these people will get extra benefit from something they "know" is better even though it's not.

And yet you believe yourself to be immune from it?


It wouldn't be a question of "sticking to it", since I've never had any (not even for my doorbell). I'd have to go out and buy some specially, which would be a very odd thing to do, given what I know about how the resistance of a wire depends on its length and the gauge of the conductor, and how that can be expected to have a detrimental effect when it is comparable to the impedance of the speaker being driven. It would be even more odd, given that decent gauge (but non-esoteric) cable is so cheap.

Your attempts to paint me as someone who thinks everything looks or sounds the same are very wide of the mark, and clearly demonstrate an inability to read my posts properly.

One thing that is perhaps rather telling about all this.

A very great deal of the music and video that people are trying to enhance with their 3 grand mains leads will have been produced in a recording or TV studio somewhere. Now what does it tell you when you see a recording studio with a quarter million pound mixing desk connected to the mains with a bit of wire that costs pence per metre?

Surely they should be breaking down the doors of places like Russ Andrews for the very best kit to ensure that they make the very finest sounding recording possible?

Surely by not using all these exotic cables to ensure the very best possible quality the recording studios are degrading the sound before we punters even get a chance to listen to it? So why bother with spending thousandds of pounds on a mains lead when the music is seriously compromised in the first place?

After all the old sayings go "garbage in garbage out" and "you can't make a silk purse from a sow's ear". So if the recording is sonically compromised from the start because the recording studio has used bog standard copper wire mains leads then how can we mere end users hope to make it sound any better??

How am I immune to it ?

I can read your posts as clearly as anyone elses.

Double standards comes to mind.

Exactly. The maximum possible quality of a recording will always be limited to the weakest link in the chain. If you've ever seen inside a recording studio you'd be amazed at the racks of equipment connected up with bog-standard cable. Good quality cable, mind, designed to minimise losses and reject interference; but not exotica made from unobtanium.

Anyway, I can't stop. I'm off to call Sky and ask them to replace the 20m run of co-ax from my dish with oxygen-free directional Monster cabling to see if it gives me richer reds and darker blacks

thats why I said I am sceptical about there being a difference for picture quality.

However without seeing a telly with one I cant comment and did say I would have to see one in operation......... I just dont discount it.

The proof is in the pudding

I have no idea. You tell me!

Except, of course, that the recording process includes lots of technology to ensure the quality and integrity of the recording, something your average CD player doesn't have.

However good quality mains cables can make a difference as I've found out for myself.

When I connected my AV system to my hi-fi I had mains hum on the centre speaker. I tried everything I, and the equipment manufacturer could think of, but with no success. A friend of mine suggested I try his QED mains leads and that cleared the problem. I tried the manufacturer's supplied mains cables again and the problem returned. By going through all the equipment we found the unit causing the problem and a £20 mains lead fixed it.

There's no doubting the power of the placebo effect. But it shouldn't be the automatic answer whenever someone reports hearing or seeing a difference that plebeian thinking can't explain.

I still maintain that those who run off and hide behind the shelter of placebo and double blind ABX may have only limited experience of the sort of equipment capable of showing the differences.

The offer I made before still stands...


The venue is nr Stockport. The time is a Thursday afternoon/evening to suit. Blindfolds entirely optional

Would you care to tell us what that technology is, exactly?


Sounds like a ground loop caused by a faulty earth in the cable you replaced. In other words, the original cable was faulty. Or are you saying you tried several other cheap cables too, and the hum persisted?

In any case, elimination of troublesome hum is not a claim routinely made for exotic power cables. Furthermore, I accept that the one you used was very much at the pauper's end of the market, and I reserve most of my vitriol for the purveyors of power cables costing many times that amount!

There's plenty of technology used to remove noise and other variables from a sound recording.


I knew it was an earth loop, I've got a HND in Electrical and Electronic Engineering and I've worked as a product support engineer on optical telecomms products for the last 20 years or more, so I'd like to think I have some idea of electronics.

I replaced all of the cables with equivalent "standard" mains leads with the same result, so it certainly wasn't simply a faulty cable.

I certainly wouldn't go around spending vast sums of money on over-priced cables, and the like, but quite often a small investment is slightly better cables can have a positive effect.

To me it's up to the individual to decide for themselves if they think there is an improvement and, more importantly, whether the outlay is justified for any improvement they think they've heard.

Not really the comprehensive answer I was hoping for.


You agree it was an earth loop, you claim it was fixed (eventually) by replacing a single mains cable, and yet you argue that the original cable (or cables?) did not have an inadequate earth?

I'm afraid I'm not clear what you think the replacement cable is doing that the original was not.

I also repeat my point about hum elimination not being the primary selling point for "exotic" mains cables. Indeed, I don't think I've ever seen it mentioned. What I have seen (for example) are claims about £700+ mains cables employing "technology that dampens musically destructive electrical standing wave reflections."

I think the fault is more likely to be in the unit rather than a cable, however it works now and I'm not going to worry too much about it.

I never made the point the more "exotic" mains cables resolve mains hum issue, as you say it wouldn't be a "sexy" enough selling point.

However your last point sums up the problem with much of the "hi-fi" industry, selling products claiming impressive things to people with no technical understanding of what the claim is trying to make. As someone who has worked in the telecomms industry for the last 20 years and before that served in the RAF working on ground radar and high-power UHF and VHF transmitters I know a claim that a mains cable can "dampens musically destructive electrical standing wave reflections" is complete nonsense, however as PT Barnum said: "There's a sucker born every minute".

No matter how hard you try, some people just can't be saved from themselves.

did glawster just change sides?

starting with

However good quality mains cables can make a difference as I've found out for myself.

ending with

"There's a sucker born every minute".


over the last 3 posts his position on the placebo effect of expensive mains cables eliminating mains hum did a full 180 or was that just me?

Hmm...I wonder, if I replace the lead on my electric fryer with a better quality one - will the chips be any better?

You never know...

But you'll have to do a double blind ABX test just to be sure and you might get fat with all those chips

Not at all. I think there's a great deal of difference between buying a mains cable costing £20 and one costing £700+! All I am saying is that the £20 mains cable, which I borrowed from a friend, resolved an issue I had. And to suggest that hearing mains hum with the standard cable and not hearing mains hum with the more expensive cable is simply a "placebo effect" is frankly an insult. As an engineer I know that a test is only truly valid if it is repeatable and we repeated the test several times with a consistent result every time.

I've made no claim what-so-ever that the £20 mains cable improved the performance of my hi-fi or anything else and I certainly wouldn't spend vast sums of money on something for a perceived improvement that I'd been told by the sales person I would get.

In saying that, though, if someone has more money than they know what to do with, what right do I, or anyone else, for that matter, have to criticize how they spend their money?