Burn-in testing - real or imaginary?

[Pdxwayne]

I'm guessing your question was about electronics in particular, right?
Anyway, regarding headphones: https://www.rtings.com/headphones/learn/break-in

Hmm, I thought I see amplitude differences of 0.5 to 1db in certain freq..The author simply assume no one can sense the differences and cast it aside?

 

[Pdxwayne]

I did, decades ago, but on speakers with a series of measurements and DBTs. No proof, no idea what happened to my box of notes from ca. 1984, lost or misplaced in some move long since then (they made it to CO from MO but disappeared in our last move, about 25 years ago now, along with several other boxes -- we finally decided the moving company must have misplaced a load but far too late to file a claim, especially as we don't know exactly what all is missing).

And the results?

 

[DonH56]

And the results?

No change after a few seconds or perhaps a minute or two of playing except for Magnepan. They did pick up a little bass after a few hours, think it was all done by 10 hours or so if not before. We ran the test for 100 hours. It was a long time ago. There were minor measurable differences on the other speakers (B&W 801, Polk something or over, don't remember the others off-hand -- six different speakers) but inaudible. For that matter, the changes on the Maggies was not picked up on in the DBTs, probably too low in frequency.

 

[Ingenieur]

Speakers and cartridges may require a few hours of break-in (not burn in) to free up mechanically. Can you hear it? In my case likely not.

Electronics: perhaps warm up, SS probably settles bias/DC offset in a minute or two, turn it on, pick some music, play music, warmed up after first song.

Tubes: not sure, but I would think 5 minutes of warm-up is plenty, a few minutes of music seals the deal.

100's of hours? Imo silly

 

[egellings]

I suspect that burn-in is the listener burning in to the new component or cable. It's called getting used to the sound variation, if any.

 

[Katji]

Why does "burning-in" always improve the sound?

...Although we do often see people selling something they bought just a few weeks before.

 

[Pdxwayne]

My Onkyo AVR had a well known no sound output issue after many years of usage. YouTube fix is to use heat gun on a chip on the board for a certain amount of time.

That tips worked for me.

Definitely for me "burn in" helped me have sound for my Onkyo AVR. 100% improvement. ; P

 

[Wes]

I suspect that burn-in is the listener burning in to the new component or cable. It's called getting used to the sound variation, if any.

That's right. The answer to the OP is that your imagination (or mentation) is real. Even small subsets of your CNS will accommodate to stimuli.

It's always possible that some changes occur in the playback system too - I'd bet on the speakers, and against the electronics.

 

[MakeMineVinyl]

My Onkyo AVR had a well known no sound output issue after many years of usage. YouTube fix is to use heat gun on a chip on the board for a certain amount of time.

That tips worked for me.

Definitely for me "burn in" helped me have sound for my Onkyo AVR. 100% improvement. ; P

Sounds like poor soldering; heating it up re-flowed the solder enough to restore contact.

 

[restorer-john]

Speakers sound their best when you first start playing music through them. If you listen at elevated levels for extended periods, they tend to deteriorate (change) somewhat as they warm up. Small speakers are the most obvious when it comes to compression/spectral changes from VC temperature. I can hear it across all my smaller 2 way speakers. Nothing imagined there- its obvious. Let the speakers cool down and all is well again.

Larger 3 way speakers with decent diameter voice coils, big magnet structures and larger cones are more immune to the thermal effects. They handle more power and move more air too.

Class AB amplifiers definitely improve in the first 5-10 minutes of operation. It's easily quantified with low level crossover distortion testing through the warmup phase until bias stabilizes.

 

[Spkrdctr]

I can tell you with absolute certainty that burning in audio equipment changes the sound. When I was much younger it was called letting the smoke out. Usually you couldn't hear anything after that. So, yes, it changes the sound or lack thereof dramatically. See, now that's what real burning is is all about. While you guys are all stunned at this information, I will exit the back door before I'm thrown out! LOL

I do enjoy this site. So many discussions on so many topics. It is a smorgasbord for the audio brain.

 

[sq225917]

It depends on the circuit.

I build a zero feedback, discrete phonostage with Wilson current mirrors supplying the input and riaa stages, each powered by their own banks of lytics. It runs very little current, and uses a slow servo to correct dc offset (mainly thermal in cause). It absolutely takes 70 hours to settle after first power up. Dc offset at output drops from +/- a few hundred mV to sub mV over this period. Once it reaches equilibrium it doesn't occur again.

It's the leakage on the caps settling as they first form. Big caps, small voltage and tiny current flow in the circuit. Happens every time.

Can't say the sound changes wildly, but operating conditions absolutely do.

 

[Spkrdctr]

It depends on the circuit.

I build a zero feedback, discrete phonostage with Wilson current mirrors supplying the input and riaa stages, each powered by their own banks of lytics. It runs very little current, and uses a slow servo to correct dc offset (mainly thermal in cause). It absolutely takes 70 hours to settle after first power up. Dc offset at output drops from +/- a few hundred mV to sub mV over this period. Once it reaches equilibrium it doesn't occur again.

It's the leakage on the caps settling as they first form. Big caps, small voltage and tiny current flow in the circuit. Happens every time.

Can't say the sound changes wildly, but operating conditions absolutely do.

Hey don't try and confuse me with data! The issue is as you stated after that initial burn in, it does not matter to the end user. No need for a "double burn in". For speakers and wires/interconnects it is really not an issue. No burn in is fine for the average listener. A bit of use and it's all set.

 

[sq225917]

Once it's burnt in, it's burnt in, long before it leaves my test bench. It runs wideband class A shunt regs as well, but they're stable a minute after switch on.

But generally speaking, burn in is rare, warm up, not so rare. But anyone selling you burnt in cables or anything else of that ilk is lifting your leg.

 

[Wes]

I can tell you with absolute certainty that burning in audio equipment changes the sound. When I was much younger it was called letting the smoke out. Usually you couldn't hear anything after that. So, yes, it changes the sound or lack thereof dramatically. See, now that's what real burning is is all about. While you guys are all stunned at this information, I will exit the back door before I'm thrown out! LOL

I do enjoy this site. So many discussions on so many topics. It is a smorgasbord for the audio brain.

How did you determine that the effects you perceived were due to the equipment, and not to neural accomodation on your part?

 

[solderdude]

How did you determine that the effects you perceived were due to the equipment, and not to neural accomodation on your part?

He mentioned 'letting the smoke out'... burning in... and it doesn't work afterwards.
I thought the phrase was 'letting the magic smoke out'.

To be honest.. I have encountered a few times that when you switch off a DUT, that lets out the magic smoke, quick enough you can repeat that action a few times.

Definitely for me "burn in" helped me have sound for my Onkyo AVR.

reflow did

The problem for such advice is this: if a blind test is taking long enough, the device would have burn in (if indeed there is such thing as burn in and how ever brief it is) and I would have failed the blind test.

I can tell you this. For a day job I design, build and service railway sensor technology (based on fibre optic sensors).
Of course all of these devices (in the thousands) are all thoroughly tested and once every few years have to be inspected (re-measured) to see if all still works perfectly. If burn-in for analog circuits and ADC's existed I am sure I would have found any evidence.
Have been in audio for over 40 years and 30 years in service/repair. Have been tinkering with and measuring headphones for years and years. Also tested prototypes (sometimes 3 of them) and have attempted to 'prove' burn in. This is very difficult to do as one needs to fix the headphone to the test fixture for days and not move it 1mm. Then you have to test immediately, 'burn-in', test again and repeat with time intervals. You also need to make sure the temperature does not change.

I am convinced some of the burn-in comes from temperature differences, time of day when testing and long term 'burn-in' is more likely to come from pads softening up and people getting used to the sound than actual properties of the headphone changing.
Rtings, Tyll and I have done some test and did not find any 'worthwhile' changes that would warrant thinking that the sound 'changed' noticeably.

 

[sq225917]

TS parameters on speakers driver change due to break in of the surround. Easily measured, doesn't happen twice.

 

[egellings]

Spider, too.

 

[Cbdb2]

Depends on the surround material, so some speakers need more than others and some don't need any breakin.

 

[solderdude]

burn-in testing (for engineers) has a different meaning than for non-engineers.
A burn-in test usually is a long term test to check if a device does not become defective and operates within specs under maximum (or close to it) conditions. It is not to 'get parts to perform optimally'.

Burn-in for audiophiles is the notion that parts need to 'get upto specs' which takes time, so they believe, based on observations they had.

This is not the same as the time needed to get into an intended and optimal operation point which may be needed every time it is switched on. Not once and after it it is good.

Mechanical devices (speakers, drivers etc) may need some time to work as designed (as mentioned by a few folks) but this usually doesn't take hundreds of hours and is not 'burn-in' but 'break-in'.
As soon as people start moaning about needing so many hours one can be sure it is not 'break-in' nor 'burn-in' but 'brain-in' or caused by improved seal or other factors (temperature, time of day, compliance of pads, changes in listening rooms)