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Burn in

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andyjm's picture
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I notice that on the 'quotation' thread, the burn in nonsense has raised its head again.

As (I would guess) one of the few on this forum who has designed equipment to be burnt in I wanted to explain what it is, and what it isn't.

Electronic components suffer from high infant mortality rates - either they pack up early, or they last for ages.  If you are making equipment where failure is expensive or has consequenses (aerospace, medical etc), then you want to weed out the equipment that is going to fail early.  Running the equipment at elevated temperature accelerates the failure (many failure modes are heat / thermal stress related). If your box survives burn in, then its probably going to last for at least its designed lifetime. This is burn in.

What burn in is not, is some miraculous process whereby components somehow drift into spec over a period of usage.  Amplifiers are not like Ford Mondeo gearboxes, they dont need to rub the parts together for 3 months for them to work properly.  The following link is to Radiospares, a company that supplies electronic components.  Each component has an online data sheet.  See if you can spot a component that refers to the parameters changing and needing to be burnt in.  I can't.

www.uk.rs-online.com

So how did this burn in nonsense start? My guess is that some HiFi hack confused 'running in' - which is a valid requirement of mechanical systems (speakers may well benefit from running in, for example), with burning in - which as I explained above is about failure rates.

As for burning in cables, this only illustrates the paucity of technical eduacation in schools these days. 

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John Duncan's picture
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RE: Burn in

Again with the thick children.

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cheeseboy's picture
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RE: Burn in

just chalk it up to another one of the many wierd and wonderful things hi fi enthusiasts want to believe will make things better yet will fly in the face of little things like facts Wink

Covenanter's picture
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RE: Burn in

What amuses me about the "burn in" idea is that the underlying assumption is that the listener's hearing remains constant and their aural memory is perfect. 

Chris

PS As has been said on other threads electrolytic capacitors do potentially change over time.  Whether the effect is large enough to hear is another matter.

chebby's picture
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RE: Burn in

andyjm wrote:

As for burning in cables, this only illustrates the paucity of technical eduacation in schools these days. 

The vast majority of the people who 'buy in' to the notion of hi-fi component burn-in are NOT kids in school (or who have recently left school). 

Component burn-in has been talked about/promoted/recommended/believed by certain manufacturers, magazine reviewers, dealers and enthusiasts for the whole of the 30 years I have been interested in hi-fi.

So you should be addressing the accusations about standards of scientific education in schools to another era. To the era when the (mostly) middle-aged folk who believe this stuff were at school.

The 'kids' and youngsters of today (and the last 10 years at least) are using headphones and  PCs, docks, MP3 players, smartphones, tablets, desk speakers, streaming services, downloads, youtube etc. etc.

You won't  find most of them coming within a country mile of the kind of dealers who advise 'burn-in'. (Nor the literature or websites that discuss it, or even  the kind of equipment it supposedly applies to.)

 

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RE: Burn in

Excellent post andyjm. I would add that mechanical components can have a bit of a wearing in or loosening up period from new. Items like speaker cones and cartidge tips and suspensions. It's also possible that valves could have a period where they change a bit as they get used from new. In my experience these effects have been subtle. Other people seem to have experienced less subtle burn-in / wear-in effects.

 

I also think that sometimes it might difficult to separate actual burn-in or wear-in from our ears and brains getting used to the presentation of new items of hi-fi equipment.

andrew_cawood's picture
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RE: Burn in

I can't claim to be very technically minded, but logically I don't understand how 'burn in' only ever seems to be positive - as if the component has an evolutionary instinct to go in the right direction. 

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RE: Burn in

andyjm wrote:
As for burning in cables, this only illustrates the paucity of technical eduacation in schools these days. 

Not to mention English...

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RE: Burn in

I'm about to receive some expensive (for me) speaker cables that the supplier has put on a "burning-in" machine for a week.

I have read quite a few reports (including distinguished hifi magazines) that things like speaker cables do change in their sound over the first 40-70ish hours of use.

As for me that would be approx 6 weeks of proper listening, this would then fall outside the acceptable returns period if I don't think they are worth the money, or sound wrong for me.

To avoid this, the supplier is burning them in for me first (at no cost). I thought that it was a reasonable precaution while everyone debates the issue.

I don't have the balance on my credit card to buy a burnt-in pair and a non-burnt-in pair at the same time to compare.

Has WHFSV done any blind testing on this subject?

 

 

 

 

 

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andyjm's picture
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RE: Burn in

altruistic.lemon wrote:

andyjm wrote:
As for burning in cables, this only illustrates the paucity of technical eduacation in schools these days. 

Not to mention English...

I'm an engineer, what can I say......

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Covenanter's picture
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RE: Burn in

DandyCobalt wrote:

Has WHFSV done any blind testing on this subject?

 

WHFSV doesn't go in for blind testing. 

Chris

chebby's picture
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RE: Burn in

DandyCobalt wrote:

I'm about to receive some expensive (for me) speaker cables that the supplier has put on a "burning-in" machine for a week.

Just to satisfy Andy's theory about cable burn-in illustrating "the paucity of technical eduacation in schools these days", have you left school recently Dandy?

 

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andyjm's picture
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RE: Burn in

DandyCobalt wrote:

I'm about to receive some expensive (for me) speaker cables that the supplier has put on a "burning-in" machine for a week.

I have read quite a few reports (including distinguished hifi magazines) that things like speaker cables do change in their sound over the first 40-70ish hours of use.

As for me that would be approx 6 weeks of proper listening, this would then fall outside the acceptable returns period if I don't think they are worth the money, or sound wrong for me.

To avoid this, the supplier is burning them in for me first (at no cost). I thought that it was a reasonable precaution while everyone debates the issue.

I don't have the balance on my credit card to buy a burnt-in pair and a non-burnt-in pair at the same time to compare.

Has WHFSV done any blind testing on this subject?

DandyCobalt,

Have you ever read a report on this subject from someone who isn't trying to sell you something?

 

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RE: Burn in

Another good post. My house mains cables burnt in after 60yrs and needed replacing

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DandyCobalt's picture
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RE: Burn in

Unfortunately, I left school a long time ago, did a science degree and my business is in a highly researched-based area of science.

(Though I gave up physics as soon as I could.)

I try and get my information from a range of sources, as I am highly sceptical of scientific claims (especially where vested interests/money/power/fame are concerned).

In fact, most of scientific research falls into these latter areas as scientists have to gain funding for their research, and compete with other scientists for their fellowships/grants/chairs/power/fame etc etc...

Where does the money come for research? Mostly from profit-making companies or to a lesser extent, governments with something to prove (eg to get re-elected).The bread on scientists' tables comes from these sources.

What happens to scientists that discover "unpopular" things? They tend to disappear into obscurity, as their funding dries up.

So I try and keep an unbiased view.

If anyone is willing to lend me a pair of 3M Tellurium Q Black speaker cables (that haven't been burnt in), then I'd be more than happy to do a scientifically controlled, double-dummy, double-blinded, placebo-(perhaps my silverscreens)-controlled test on a range of subjects - none of whom have a vested interest in hifi (whatsoever, I assure you). 

In the absence of that, if a supplier offers to "burn-in" my pair of cables, then I'll take it...just in case Smile

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RE: Burn in

chebby wrote:

The vast majority of the people who 'buy in' to the notion of hi-fi component burn-in are NOT kids in school (or who have recently left school). 

Component burn-in has been talked about/promoted/recommended/believed by certain manufacturers, magazine reviewers, dealers and enthusiasts for the whole of the 30 years I have been interested in hi-fi.

So you should be addressing the accusations about standards of scientific education in schools to another era. To the era when the (mostly) middle-aged folk who believe this stuff were at school.

I don't think that peoples age or when they left school has anything to do with it. But anyone who thinks that the conductive properties of a copper cable will change over time* clearly has a limited understanding of basic GCSE level physics.

 

* not including corrosion which is another issue entirely.

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