How much of burn-in/ break-in (in hours) is objective vs. getting used to sound?

[DaveC]

Hello Micro

No not really I am very skeptical. Here is the rub, parts do change over time and temperature but usually not enough to take a part out of it's tolerance range. My gripe is even with accelerated aging, which part screening does do, the parts are typically still in tolerance. So if you have a 5% resistor it will still be a 5% resistor after screening but it will have a shift in value. If the design can tolerate a 5% part then this shift in value should not be audible. Basically you can have a potential 10% value change from resistor to resistor right out of the box. This is much more than you would get after a couple of hundred hours of operation. You have to remember that in any application parts are not used close to their max ratings for reliability. In part screening you are intentionally hammering them to weed out potential failures. So in real world applications you should see even less change than screening.

You have hundreds of parts all shifting slightly in value that all interact with each other. Why does it always go well? Especially when part tolerance swamps any part value shifts due to "burn-in".

Rob

I'm not sure the phenomenon of burn-in has anything to do with changes in gross values of passive parts, but rather in the interaction of conductor and dielectric. The bulk of it happens over just a few hours, but most things get subtly better for a few hundred hours or more. Those who have built their own components have experienced this... most people have just experienced the more subtle longer term burn-in effects. I think it was Bob describing his 300b amp earlier, that's a good description of what it's like. No hyperbole, night and day...

 

[fas42]

Well, if you are just considering the tolerances of the basic units, we do not need to go on debating. Nothing useful will come from it. I will not learn anything from you and you will not learn anything from me. I am not here to debate rocket science and satellites, but high-end audio. It seems you are an high end skeptical - something I respect - but we we are at extreme positions. Thanks anyway.

Yes, most of the important variations are with parasitic behaviours - you know, all the things that make, say, a real capacitor a non-perfect electrical part - transformers are another beauty, in this regard. It's a sea of change, and one sails the ship of audio upon it all, trying to not be aware of the waves - possible, but not trivial to do ...

 

[Robh3606]

It's amazing how bad the litz wire sounds for the first few hours... I think this may be provable with simple frequency response measurements. I'm about to build a new litz wire speaker cable for a customer, I'll see if I can get results. I have a pair of Pioneer S-1EX with the TAD coax driver, it should work well to close-mic that driver and get decent results >400 Hz. I think 4 hours on the burner and 2 hours playing music should be enough to accomplish the great majority of burn-in and I can leave the mic in exactly the same place for the 6 hours without a problem.

Hello Dave

I would like to see the results. We use lots of litz wire but at much higher frequencies say up to a couple of gig. Semi-ridgid coax above. Typically wire effects at audio frequencies are insignificant compared to RF work. We don't have any issues just taking wire off the spools. I doubt any manufacturer of audio equipment is doing anything different that we are when they are building their amplifiers as an example.

Rob

 

[DaveC]

Hello Dave

I would like to see the results. We use lots of litz wire but at much higher frequencies say up to a couple of gig. Semi-ridgid coax above. Typically wire effects at audio frequencies are insignificant compared to RF work. We don't have any issues just taking wire off the spools. I doubt any manufacturer of audio equipment is doing anything different that we are when they are building their amplifiers as an example.

Rob

Good high frequency performance generally correlates with good performance at audio frequencies...

 

[Robh3606]

Well, if you are just considering the tolerances of the basic units, we do not need to go on debating. Nothing useful will come from it. I will not learn anything from you and you will not learn anything from me. I am not here to debate rocket science and satellites, but high-end audio. It seems you are an high end skeptical - something I respect - but we we are at extreme positions. Thanks anyway.

Hello Micro

You can't debate because you have nothing to debate with. At least I have real world experience seeing the effects of burn in at the component level where it is all well understood. I asked for a definition of audiophile burn-in. I work in an industry that actually uses it and understands the effects. If you cannot explain audiophile burn-in beyond personal anecdotes I will gladly call it Fairy Tale Burn-In and if that's the case your right we don't have anything to discuss.

Rob

 

[GaryProtein]

Another Burn-In article, this time from Pioneer Pro Audio...

http://www.pioneerproaudio.com/en/studio/casestudies/masahirokawaguchi.html#


CASE STUDIES
Masahiro Kawaguchi


. . . . Blah, Blah, Blah. . . .


- How was the first month when you were burning in the speakers?

“While I was burning in the speakers, I did notice that they were crackling at high frequencies. Tweeters still need burn-in time, even if they are coaxial units.”

Just to be clear, Case Studies and Reports are the LOWEST form of scientific evidence.

Blind and double blind studies with meta-analyses and randomized controlled trials are what counts.

Why are the requirements for all scientific studies disregarded in audio? ? ? ?

 

[Robh3606]

Good high frequency performance generally correlates with good performance at audio frequencies...

Hello Dave

Ok that's usually a given but we don't screen coax cable as an example. I have been doing this for a long time and have never seen an out off spec condition due to wire effects aside from an open or short. We don't change out wires because a unit doesn't meet spec except for VSWR and that is at 10 gig and higher on semi-ridgid cables that are outside the scope of this discussion.

Rob

 

[DaveC]

Hello Dave

Ok that's usually a given but we don't screen coax cable as an example. I have been doing this for a long time and have never seen an out off spec condition due to wire effects aside from an open or short. We don't change out wires because a unit doesn't meet spec except for VSWR and that is at 10 gig and higher on semi-ridgid cables that are outside the scope of this discussion.

Rob

I'm not sure your work has any relation to "audiophile burn in", as I don't believe the mechanism that cause drift in gross values of passive components over their lifetime is relevant to the discussion, but I could be wrong... Hopefully the systems in your craft are fairly robust and I'd guess it's all digital... in audio we're not dealing with simple quantization with the signal simply flipping 1s and 0s, but an analog waveform being interpreted by very sensitive and sophisticated (though of questionable reliability ) equipment. Apples/oranges imo...

If you use litz wire try making a speaker cable out of it, I'm sure you'll be shocked by the incredibly obvious burn-in. Sometimes it's hard to beat doing simple experiments, especially in audio. But "flat-earthers" seem loathe to do so, and never ever agree to try my cables to see if they are actually better than their Belden cables... Not that this applies to you, but it is true most people that hold firm beliefs won't allow them to be challenged, even if the beliefs are formed on the basis of little information and no real experience. And yes, it can go both ways...

 

[BobShermanEsq]

Just to be clear, Case Studies and Reports are the LOWEST form of scientific evidence.

Blind and double blind studies with meta-analyses and randomized controlled trials are what counts.

Why are the requirements for all scientific studies disregarded in audio? ? ? ?

Charts can be very informative.



http://www.shorpy.com/node/2194

http://query.nytimes.com/gst/abstract.html?res=9D00EFD8163DE633A2575BC2A96F9C946296D6CF&legacy=true

 

[Robh3606]

Hopefully the systems in your craft are fairly robust and I'd guess it's all digital...

Hello Dave

No analog to 20 gig So DC up to 20 Gig all analog. We build precision oscillators and cover the whole gamut from 100 Hz and up.

But "flat-earthers" seem loathe to do so, and never ever agree to try my cables to see if they are actually better than their Belden cables... Not that this applies to you, but it is true most people that hold firm beliefs won't allow them to be challenged, even if the beliefs are formed on the basis of little information and no real experience. And yes, it can go both ways...

Am I a flat-earther because my professional experience contradicts what I read on audio forums? I am still waiting for a definition of audiophile burn in. I am sorry but if you think for a moment you have anything over the guys who designed the Space Station and all the planetary probes like Voyager, Cassini, the JPL guys lets keep going Hubble and so on. All of which we have boxes on you are kidding yourselves.

Rob

 

[BobShermanEsq]

the Space Station and all the planetary probes like Voyager, Cassini, the JPL guys lets keep going Hubble and so on. All of which we have boxes on you are kidding yourselves.

Rob

But do any of them play music? If not they are applicable to the conversation IMO.

 

[DaveC]

No analog to 20 gig So DC up to 20 Gig all analog.



Am I a flat-earther because my professional experience contradicts what I read on audio forums? I am still waiting for a definition of audiophile burn in. I am sorry but if you think for a moment you have anything over the guys who designed the Space Station and all the planetary probes like Voyager, Cassini, the JPL guys lets keep going Hubble and so on. All of which we have boxes on you are kidding yourselves.

Rob

In audio maybe I do... I've compared my cables to MasterBuilt (Delphi Aerospace) and mine were head and shoulders better, MB wasn't even close.

 

[Robh3606]

But do any of them play music? If not they are applicable to the conversation IMO.

Hello Bob

No but what they do is much more demanding in a very demanding environment. Little bit harder than your typical livingroom with respect to temperature and radiation. Music is a joke as far as bandwidth is concerned. Sorry but when your bandwidth is a gig or more and your gain flatness is a .1 db over the bandwidth and temperature then we can talk.

Rob

 

[Robh3606]

In audio maybe I do... I've compared my cables to MasterBuilt (Delphi Aerospace) and mine were head and shoulders better, MB wasn't even close.

Hello Dave

I didn't mean it as a personal challenge. I am stating where I am coming from. It would be great if someone could correlate what you/they hear with some kind of accepted or new measurement to explain what's going. I was happy you would even consider trying to see if you could see what you hear in a simple frequency measurement. To me that's a step right direction.

Rob

 

[fas42]

The trouble is ... what counts in music is signal to noise - in space, there can be tonnes of electrical rubbish - no worries, retry until success, add massive redundancy, error checking. With playback there is a single go at getting it right - and if there's a pattern in the lack of quality then the mind can latch on to it ... and then the system gets a fail ...

 

[jankoluvsky]

there is any different quality sound if we burn first than ordinary use ?

 

[LL21]

Hello Micro

No not really I am very skeptical. Here is the rub, parts do change over time and temperature but usually not enough to take a part out of it's tolerance range. My gripe is even with accelerated aging, which part screening does do, the parts are typically still in tolerance. So if you have a 5% resistor it will still be a 5% resistor after screening but it will have a shift in value. If the design can tolerate a 5% part then this shift in value should not be audible. Basically you can have a potential 10% value change from resistor to resistor right out of the box. This is much more than you would get after a couple of hundred hours of operation. You have to remember that in any application parts are not used close to their max ratings for reliability. In part screening you are intentionally hammering them to weed out potential failures. So in real world applications you should see even less change than screening.

You have hundreds of parts all shifting slightly in value that all interact with each other. Why does it always go well? Especially when part tolerance swamps any part value shifts due to "burn-in".

Rob

Hi Rob - question in the spirit of learning and asking, not challenging:

If tubes were originally designed for military spec (equipment that was [literally] mission critical like submarines, etc)...is it acceptable to say that MIL SPEC tubes are inconsistent by audiophile standards given the fact that, as many will attest, you stick in a pair off the shelf and some are noisy, some are not...some last 3,000 hours, some 5,000 hours before they get noisy?

So from the standpoint of using the tube for function military equipment, we imagine 'mil spec' to be quite high where technicians were almost certainly not putting in tubes for an hour and then pulling them out because "they were noisy"...and yet grab 10 tubes off the shelf (newly manufactured, not even NOS), and some have noise, some have no noise, some go noisy in 1.5 years, others in 3 years or more.

We then couple that with the "observation" that many people on the street would listen to any one of our systems...compare it to something mid-fi off the street...and say "i dont think there's much difference"...just give me an ipod and some cheap buds...you guys are all crazy to care about stupid itty, bitty little changes to bits of sound...the tune is the same stupid tune.

Is it possible that in our systems, all of these tubes are operating well within their spec...the system is making music afterall and functioning...but audiophiles are, in fact, pushing their systems to operate within even tighter tolerances? After all, even with tube noise, the system "works perfectly" by a lot of people's standards...turn it on, music comes out...a bit more hiss now than 1 year ago? Really? You are audiophile guys are nuts.

coming back to the question...based on the above, would you say that audiophiles are actually seeking to operate equipment to within tighter tolerances than the manufacturer considers to be 'fully operational'?

 

[LL21]

another example of tech specs 'being well within tolerance' and yet an audiophile might consider 2 'identical units' or products to be quite different.

i buy 2 laptops (identical)...i run them, play with them for 6 months doing the identical tasks. they probably both run within the same tolerance of performance...but i bet the number of times one unit might crash during those 6 months will be different than another. Do slightly different units or different uses/setups with the same piece of equipmet (like audiophiles who might play their system harder/less hard than others, have different grids, difference impedances between equipment, etc.) have different performance levels (when being super nitpicky) that are all well within "manufacturing tolerances"?

i think of my [supposely] super reliable toshiba laptop and it has certain crashed more times than the same one with others who own same model. And yet it still works "fine" by manufacturing standards...no way they give me a new one because this is "outside of specification". And yet, if i were a super-performance-freak techno-guy, i would almost certainly be swapping out some chip inside because this one crashes more often than "optimal".

 

[microstrip]

Hello Micro

You can't debate because you have nothing to debate with. At least I have real world experience seeing the effects of burn in at the component level where it is all well understood. I asked for a definition of audiophile burn-in. I work in an industry that actually uses it and understands the effects. If you cannot explain audiophile burn-in beyond personal anecdotes I will gladly call it Fairy Tale Burn-In and if that's the case your right we don't have anything to discuss.

Rob

Rob,

A terrible mistake. Your industry uses burn-in in completely different conditions with different purposes. It has no interest at all in the very small effects we are debating in audiophile forums. Just because the audiophiles use the same word does not make you specialist in audiophile burn-in, some thing that has been well described in this forum by many people.

BTW, in gaseous radiation detectors, that use insulators such as Kapton or Teflon, we have a related effect that we call "conditioning". We do not have exact scientific explanations for it, but know it can be related to dielectric relaxation, ionic conduction, migration of defects or charge recombination. I am sure that if the people writing books such as "Handbook of Low and High Dielectric Constant Materials and Their Applications" would decide to spend a few years of their life studying audiophile burn-in or detector conditioning, we would have a lot of science on it. Until then, all we have is empirical knowledge based on user experience, that we apply everyday.

Until then, as you say and I accept it is Fairy Tale Burn-In. Fortunately Harman/JBL also decided to use Fairy Tale Polarization of film capacitors in their speakers, audiophiles feel in good company.

 

[amirm]

another example of tech specs 'being well within tolerance' and yet an audiophile might consider 2 'identical units' or products to be quite different.

i buy 2 laptops (identical)...i run them, play with them for 6 months doing the identical tasks. they probably both run within the same tolerance of performance...but i bet the number of times one unit might crash during those 6 months will be different than another. Do slightly different units or different uses/setups with the same piece of equipmet (like audiophiles who might play their system harder/less hard than others, have different grids, difference impedances between equipment, etc.) have different performance levels (when being super nitpicky) that are all well within "manufacturing tolerances"?

i think of my [supposely] super reliable toshiba laptop and it has certain crashed more times than the same one with others who own same model. And yet it still works "fine" by manufacturing standards...no way they give me a new one because this is "outside of specification". And yet, if i were a super-performance-freak techno-guy, i would almost certainly be swapping out some chip inside because this one crashes more often than "optimal".

There are no electronic parts that are identical to each other. Indeed, there are large variations. An IC may use have nominal power consumption of 5 watts but actual parts may vary from 4 to 6 watts. And some outliers as much as 9 or 10 watts! Now imagine every component out of thousands in your system (computer or otherwise) having such variations. The combinations are infinite and indeed, no design is verified to work across all of them. Some combination of parts will fail completely, and some fail more often as you say. Monte Carlo simulations can be run to better quantify this problem but in general, it is ignored.

In the case of computers crashing, that can happen due to latent bugs that are in the operating system or even the CPU. Different usage patterns may hit on them, or not. 30 years ago I worked on debugging a CPU where if an external event happened in under 1 microsecond it would cause the CPU to corrupt memory causing a crash.

Back to the topic at hand, there are such large variations in the circuit components that there bettery be no reliance on them being the same, or arriving at some value due to burn-in. During soldering, components are subjected to 200 degree temps and will cause them to age at rates far, far more than any "burn in" could ever do. Designs obvious need to withstand and remain performant regardless. And certainly so in high-end gear where one is paying a lot more for precision products.