[buggalugs]

A thesis has been lodged in a UK university (I am trying to find the details) which demonstrated that burn in IS a fact and caused by favoured pathways being generated by what can be best described as electron "burrowing" in conductive materials.
The effects were repeatable and measurable so there is no doubt that the perceived improvements in some HI FI gear from increased use from new is genuine.

 

[Dane]

IMO, any technical or scientific explanations first become relevant once the effect has been confirmed (DBT

). Even if measurements reveal burn-in as a physical fact it is still not evidence that some humans can detect this.

Anyone happen to be the owner of two identical amps where one has never been used? No? I thought so

 

[GWN]

I've never owned two pieces of identical equipment but I do have the opportunity to listen to and burn-in a wide variety of equipment that I set-up and service for two local shop. Working for two different audio shops and being good friends with both the owners allows me to sample a wide variety of components in my home. And yes I have had two pieces of gear in the house one that had been in service for a while and a brand new one, most notably the Hovland Radia amp and HP100 pre-amp, YBA Passion integrated and Clearaudio and Benz cartridges. I also have a Nordost cable cooker which I use to burn-in the stores cables. Burn-in is real. Most noticeable with speakers followed by phono cartridges, tube gear and to a lesser extent amps and pre-amps. Anything that has Hovland or Blackgate caps takes quite a while to settle down. Universal, yes I think so. Last year I listened to a wide variety of components including 23 pre-amps, 12 power amps/integrated, 15 CD/SACD players, 8 speakers, set-up 15 turntables and cartridges, 29 power cords and about the same amount of interconnects.

 

[JohnFerrier]

Sounds interesting, but the original poster is asking for a scientific explanation. I don't think there is one.

*EDIT* Doing some other surfing I ran across this:
http://www.referencerecordings.com/SAMPLE.HTML

It's a test and burn-in CD for those that need it...


JF

 

[purk]

I do believe in burn in. For instance, the old Sony MDR-E888 sounds noticably different than the out of package one. The old one has a significant treble roll off, while the bass becomes more prominant. I don't know whether burn in is true in amp or source, but many audiophiles seem to believe them. For example, Zu cable said that allow the cable to burn in for a period of time to reach its optimum performance.

 

[PinkFloyd]

http://www.rock-grotto.co.uk/warmup.htm my two cents worth.

 

[fewtch]

Quote:

Originally posted by PinkFloyd http://www.rock-grotto.co.uk/warmup.htm my two cents worth.

Interesting you feel modern solid-state equipment (particularly op-amp based stuff) takes time to "warm up." I'd agree with tube-based equipment, but have my doubts with SS gear (at most, it's gotta be a few seconds for even the biggest caps to charge fully). My ears tend to bear me out on this, but maybe there's something I'm missing...

P.S. re your choice of op-amps for the Chiarra... nice to see you chose the AD823AN. I share your liking of the Analogue Devices sonic signature (with the Mint and Meta42 anyway)... just so sweet, liquid and satisfying. Seems the AD8610/20 have fallen out of favor with the advent of the PPA, but my ears refuse to follow trends

.

 

[Earwax]

Quote:

Originally posted by fewtch Interesting you feel modern solid-state equipment (particularly op-amp based stuff) takes time to "warm up." I'd agree with tube-based equipment, but have my doubts with SS gear (at most, it's gotta be a few seconds for even the biggest caps to charge fully). My ears tend to bear me out on this, but maybe there's something I'm missing...

My 1986 D-5a CDP takes about 10 minutes to warm up, it's noticeabley harsh when first turned on. Some other old solid state CDPs have taken about 5 minutes to warm up. Maybe the old stuff has larger chips and capacitors that take a little longer to reach operating temperature than newer stuff.

 

[fewtch]

Quote:

Originally posted by Earwax My 1986 D-5a CDP takes about 10 minutes to warm up, it's noticeabley harsh when first turned on. Some other old solid state CDPs have taken about 5 minutes to warm up. Maybe the old stuff has larger chips and capacitors that take a little longer to reach operating temperature than newer stuff.

Well, stuff that's mostly discreet takes time to even out in temperature... e.g. certain types of transistors tend to perform at different specs depending on temperature (the main reason why the first Moog synthesizers in the mid 60's drifted out of tune so often).

With stuff like the Chiarra amp (an op amp and a few widely spaced components) I wonder why it would take time for such a piece to warm up.

 

[PinkFloyd]

Quote:

Originally posted by fewtch Interesting you feel modern solid-state equipment (particularly op-amp based stuff) takes time to "warm up." I'd agree with tube-based equipment, but have my doubts with SS gear (at most, it's gotta be a few seconds for even the biggest caps to charge fully). My ears tend to bear me out on this, but maybe there's something I'm missing... P.S. re your choice of op-amps for the Chiarra... nice to see you chose the AD823AN. I share your liking of the Analogue Devices sonic signature (with the Mint and Meta42 anyway)... just so sweet, liquid and satisfying. Seems the AD8610/20 have fallen out of favor with the advent of the PPA, but my ears refuse to follow trends .

Hi fewtch,

I have always found solid state equipment to sound "cold" and clinical whenever it's first switched on. If I let it warm up for an hour or two and then go back to listening to it it's immediately obvious that the sound has become a lot better, it actually sounds "warmer" if that makes any sense?

"Burn in" should probably be renamed "break in" Burn in is what some manufacturers do to test the circuits to the limits before passing them in QC. They "soak test" the circuits under extreme heat conditions for say 48 hours and stress the components way beyond anything experienced during everyday operation. If the device passes this test it is sent out to the customer. I worked for a company in the early 90's and their soak test failure rate was about 25%. The circuit would go to the fault finding section and the failed component would be replaced and then the circuit would go in for a second 48 hour soak test. I can tell you from experience, a human wouldn't survive for 48 hours in the soak test room it was b*stard HOT!! The majority of failures were capacitors.

"Break-in" is an entirely different thing. It takes time establishing the electron flow on the PC board, it takes time for capacitors to "fully" charge and reach a stable operating condition etc. I believe that "break-in" is a fact and it's something that happens with everything, not just Hi-Fi...... shoes, cars, hats, drums, gloves, lawnmowers,,,,, you name it. I must rename that page to "break-in"

The AD823 was superb in the Chiarra fewtch but I'm now using OPA627 BP's on a browndog which sound a bit better. I put this down to a seperate op amp for each channel as opposed to the all in one dual chip. The difference is not night and day though but after prolonged listening the 627's won me over

Pinkie. (breaking in a new keyboard and mouse)

 

[PinkFloyd]

Quote:

Originally posted by fewtch Well, stuff that's mostly discreet takes time to even out in temperature... e.g. certain types of transistors tend to perform at different specs depending on temperature (the main reason why the first Moog synthesizers in the mid 60's drifted out of tune so often). With stuff like the Chiarra amp (an op amp and a few widely spaced components) I wonder why it would take time for such a piece to warm up.

The Chiarra is pure class A and those babies ain't happy unless they're roasting hot

PS: the gspaudio Solo sounds absolutely awful from cold (and I mean DIRE) Graham Slee advises that it's left constantly powered up. I turned it off after it had been on for a couple of months as I was going away for the night..... the following day I switched it on again and it sounded bl**dy awful for about 6 hours.... I don't know if it's a UK thing but most of the people I know leave their equipment powered up 24/7 365 maybe switching off once a year to clean the phono sockets etc.

Maybe we've just got more sensitive ears over here?

 

[fewtch]

Quote:

Originally posted by PinkFloyd The AD823 was superb in the Chiarra fewtch but I'm now using OPA627 BP's on a browndog which sound a bit better. I put this down to a seperate op amp for each channel as opposed to the all in one dual chip. The difference is not night and day though but after prolonged listening the 627's won me over

The 627(BP) seems to be the main op-amp in favour these days (maybe the 637 as well). I tried these with my Senn HD600s in a Meta42 and didn't like what I heard at all.... they sounded sort of "dead" to my ears. Perhaps this is a typical "audiophile" or tube-ish sort of sound (which I really don't much like either

). What sounds warm and full to many people seems to sound gooey and thick to my ears (like chocolate that's too rich). I guess it's purely a matter of personal taste.

It's funny, but my phono cartridge of choice has fallen out of favor lately at AudioAsylum (has a thin, bright sound to some ears). I guess I prefer a thinner sort of sound over the "fullness" that seems to turn most people on. The same thing happened with the Oehlbach Senn cable... I much prefer the stock (reputed to be thin sounding).
Quote:

Originally posted by PinkFloyd I don't know if it's a UK thing but most of the people I know leave their equipment powered up 24/7 365 maybe switching off once a year to clean the phono sockets etc. Maybe we've just got more sensitive ears over here?

I can't with my (digital source) amp, I'm using it with a 16-cell NiMH battery pack. I'll take the tradeoff in ultra-clean power over any SQ hit caused by turning the amp off between listening sessions.

 

[PinkFloyd]

Quote:

Originally posted by fewtch The 627(BP) seems to be the main op-amp in favour these days (maybe the 637 as well). I tried these with my Senn HD600s in a Meta42 and didn't like what I heard at all.... they sounded sort of "dead" to my ears. Perhaps this is a typical "audiophile" or tube-ish sort of sound (which I really don't much like either ). What sounds warm and full to many people seems to sound gooey and thick to my ears (like chocolate that's too rich). I guess it's purely a matter of personal taste. It's funny, but my phono cartridge of choice has fallen out of favor a great deal lately as well (has a thin, bright sound to some ears). I guess I prefer a thinner sort of sound over the "fullness" that seems to turn most people on. The same thing happened with the Oehlbach Senn cable... I much prefer the stock (reputed to be thin sounding). I can't with my (digital source) amp, I'm using it with a 16-cell NiMH battery pack. I'll take the tradeoff in ultra-clean power over any SQ hit caused by turning the amp off between listening sessions.

The TI op amps, in general, do sound very chocolaty I couldn't agree more. The 627 in the Chiarra bucks the trend however and my ears like what they hear At the end of the day, it's all down to personal choice and all of our ears as as unique as our fingerprints (no two being alike) so I tend not to get drawn into the "flavour of the month" as I know the only way to evaluate something is to use your own ears........ after all it's you who will be listening to the music.

Having said that, it's always interesting to read a second parties opinion and that's what head-fi is all about. Anyone reading this thread....... use your ears as the final judge. What may sound "awesome" to someone else may sound utter crap to you......... Use your ears, if it sounds good then it's good for you.

Pinkie.

 

[elnero]

Quote:

Originally posted by mojoman How come burn in never results in a component sounding worse then when it was new?

Probably because most manufacturers design with break-in in mind. Some of the more mass market manufacturers probably won't subscribe to the idea but in my experience most high end manufacturers do.

This has been argued over and over and I don't really want to get into it again but I would like to point out a couple of things.

First off, I will say that every component is going to be different, sometimes there will be noticable differences, other times they will be negligble and then there will be particular people that will never hear a difference either because they can't or don't want to. We all hear differently, some better than others and that's just a reality of life. Just because one person has never heard the effects does not mean they don't exist.

FWIW, my new Cambridge Azur 640C stated right on the box that it needed at least 36 hours before it would sound it's best and thereafter a warmup period of 10 - 15 min. was recommended.

I also worked for a speaker manufacturer at one time. Before any speaker was sent out the door we did a 24 hour break-in period but also stated that more would be required by the new owners before they would sound their best.

 

[JohnFerrier]

If you believe in lucky charms, someone will sell you lucky charms...doesn't make it real.


JF