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Mains quality doesn't matter.?

All that article does is confirm that it is largely irrelevant.

Philip Harrison, from JP French Associates, another forensic audio laboratory that has been logging the hum for several years, says: "Even if [the hum] is picked up at a very low level that you cannot hear, we can extract this information."
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That information is extracted by the use of extremely powerful filters and very high levels of gain. So in no way typical of a hi-fi system.

In any case, the article quotes scientists and refers to controlled analysis.
We know that these things are to be avoided when discussing audio ;)

I'm seeing a distinct tendency among some where they are prepared to accept science when it (appears) to support their argument, yet revert to the 'my ears know best' line when it doesn't.
 
"All that article does is confirm that it is largely irrelevant..."

LOL..I will sleep well regardless.
 
I've always thought that power is a very small part of the modern hifi given modern tech and as already mentioned its ability to filter out unwanted noise. That was until I got a naim system, the PS upgrades in naim do make a huge improvement to the sound quality. The sound improvement of just adding a flatcap to a CDP is enormous and I'm still amazed at the difference it makes.

Flip side of that story though, years ago I worked for a call recording vendor and had to install a recorder for london electricity's call centre in elephant & castle. Couldn't understand why there was such a bad hum on all the recordings until someone told me the office was built above a huge sub station and the analogue section of the recorders DAC was picking up the induced noise.

Most lawful interception vendors been using ambient noise for years to fingerprint recordings for lawful interception so this isn't new and has never required forensic scientists to validate it in court. The software will compare the fingerprint generated by the recorder against a central database and if it doesn't match will alert the end user. This has been certified for use in court cases and even supports the use of post recording compression from g711 to g729 or g723 etc as defence lawyers have argued for years that compressing recordings is altering the original as it is essentially removing data from the original.
 
The article isn't relevant to high fi, except to illustrate that sound engineers do go to some trouble to remove hum from their recordings.

The replay chain, however, is a different kettle of fish. Unless the amplifier designer is silly enough to amplify the - inaudible to us - hum, there's no reason to think mains quality has any impact. The 50hz hum is everywhere, whether we like it or not, but the good news is the level is so low we can't hear it anyway. Same goes for any minor fluctuations, as the article says.

So, bad news for the magic power chord/mains filters/ separate circuit fanboys on this level anyway.
 
Robert said:
I'm seeing a distinct tendency among some where they are prepared to accept science when it (appears) to support their argument, yet revert to the 'my ears know best' line when it doesn't.
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Ah in a similar vein to the global warming, oops, climate change brigade then ;)
 
I think the point is being missed. The hum is not (for a well designed system) coming through the mains via the direct live connection and power supply. Rather it is being induced via the aether in the same way that radio signals reach your radio. So even a battery operated recorder with no mains connection will be affected buy the ~50Hz induced signal.

Good design can reduce this to practically zero. We on this planet are swamped in photons (emr) from many different sources but good design can reject these. However with poor design your amp will pick up local radio stations, taxi drivers and the like.

You can follow what is happening on the National Grid with this frequency meter http://www.dynamicdemand.co.uk/grid.htm

Cheers,

DV
 
It isn't just 50 hertz though is it? Certainly noise is induced from the mains wiring in your house as EMI to other cabling ie dac, amplifier etc. Most (all?) houses have a dearth of SMPS now that we're all forced to have low energy lighting for example which put all sorts of rubbish onto the mains. The cheaper the SMPS the dirtier it is I would think? And if all this interference is already on the mains it must be getting directly into our equipment surely?
 
Audio and all other rectified mains connected equipment is like a dog licking its own balls.

Self Pollution

Outside influences just finish the job.
 
I used to live in a flat that had a small substation next to it, it used to buzz like there was no tomorrow and I could hear this in my Hifi even before I realised it was the source of the issue.

Needless to say all the russ andrews filtering parafinalia and other branded mains filters did nowt to rid me of the hum/buzzing in my system. however a move to a new house 6 months ago and the buzzing has vanished.

Coincidence ? I think not.
 
Most of us (all?) sometimes think that our system is having an 'off' day. The most common reason offered is that the mains is polluted at that time. If this is untrue, then what causes these performamnce fluctuations?
I think the only other sensible explanation is that the 'fluctuations' are actually in our moods. The variable is us human beings, not the equipment. Which, of course, opens a whole new can of worms.
 
paskinn said:
Most of us (all?) sometimes think that our system is having an 'off' day. The most common reason offered is that the mains is polluted at that time. If this is untrue, then what causes these performamnce fluctuations?
I think the only other sensible explanation is that the 'fluctuations' are actually in our moods. The variable is us human beings, not the equipment. Which, of course, opens a whole new can of worms.
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Have you seen the new Nordost Audiophile Worms?
 
I will no doubt be told that my system is not revealing enough or that my hearing is not educated enough to hear the subtle differences but if anybody is trying to decide whether to by power conditioners, cables or audiophool wall sockets let me give you a glimpse into a cautionary tale.

My electric supply was not even connected for 3 weeks and nobody noticed a jot of difference...

“Thank you for sending your engineer last night. He confirmed that everything had now been done correctly and that your meter had not been worked on or inadvertently altered in any way by our electrician.
Following discussions with both the engineer and my contacts we thought it wise that we clarify a few things as we see them -
a) we were lead to believe that the responsibilitys of the electrician who fitted the meter ended with your meter and everything your side of it. We have now been informed that he is also supposed to check all connections to it. All connections should be properly secured.They are supposed to check that the insulation covering the wires goes all the way into every fitting and no un-insulated wire is showing. This was not done.
b) in my conversation with Tim I did not simply say that part of the house had supply. What I actually said was that from your meter the supply goes to a new distribution board for the new extension and also to the old, "bakelite" fuse box, which supplies the rest of the house. It is that part which has no power. I explained that I had checked all the fuses and trips and they were all ok. We had not lost power to the lighting or the power to the cooker or other. We had lost all of it. As the only thing between the power entering from your fuse and our original fused distribution box is your newly fitted meter, ( via a Henley block which your engineer "connected" in to ) it should have been obvious that something was amiss with the new meter or fitting there-of. Your engineer seemed to agree and 3 of our subcontract electricians agree.
It was one of those subcontractors who originally pointed out that if we had a new clutch fitted in our old car and 3 weeks later it would not go into gear we would contact the garage who fitted the clutch. They would not refer us to Ford. Just because it worked fine for 3 weeks does not mean they are in the clear. As Tim seems to think.
c) we are angry at your company line that your clients should employ an electrician to come in and assess the problem. If he finds a problem with your meter a call should be made directly to you. So basically your clients should pay for an electrician to come and check your work to save you having to do it.
d) we are very angry that your lack of appropriate action put our lives at serious risk. The engineer made a mistake which could have killed us. Tim and whoever advised him made a bad judgement which could have killed us. Remind me again. Is it 230 amps that come out of your meter box !
We have asked our electrician to give us his views on the meter fitting and a copy of the photos he took of the loose wires. He is the electrician we were forced to get in on saturday, so this is our report. If you had wanted a report you should have sent your own engineer on friday. Within 4 hours of us reporting the the problem.
Can you now ensure that all communication is either by letter or email”


And yes, we did get a big "apology cheque" :cool:


The best upgrade is to go away from your stereo for a month or so then go back and listen to your favourite album. It will sound amazing. And it won't have cost you a penny.
 
paskinn said:
Most of us (all?) sometimes think that our system is having an 'off' day. The most common reason offered is that the mains is polluted at that time. If this is untrue, then what causes these performamnce fluctuations?
I think the only other sensible explanation is that the 'fluctuations' are actually in our moods. The variable is us human beings, not the equipment. Which, of course, opens a whole new can of worms.
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I think this is 100% true. The mains is hammered most of all between 6pm and 10pm.
 
I am surprised that being disconnected from the electricty supply did not affect your hifi's performance in any way.

Did you not find it rather quiet?
 
hughmc2 said:
Oh dear, the perils of reliance on spell-check. ;)
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Well, I'm buggered if I can see an error in your post; mind you, I wouldn't have a clue how to engage spell-check. Isn't it American English spell-check; not reliable in England, surely? Ah, yes, a missing 'i'; that's just a typo, but it's a useless spell-check system that didn't pick that out !.

Sorry, but I'm such a pedant that these things interest me !!!!!

Back on topic, I've long noticed that I've got consistently better s.q. in warmer weather during spring or summer. There are many variables (as someone has said) in mains 'quality', but also many in humans' receptive moods. Seems the colder the evenings ( esp.recently), the less my hifi engages me, and I've always been on underground supply.

A Wammer I know lives out in the sticks here in Norfolk, and a month or so ago, most of the villages around him suffered a power failure (overhead lines), but he did not. He said that he'd never heard his (expensive) hifi sound so good, despite the fact that he was knackered after a hard day's work. This was a one-off before the power was reinstated. Surely there can only be one explanation.
 
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