break-in--bane or boon ??

Doug, I thought that your article was excellent. Which is not say that I deny that all or even most claimed breakin phenomena are real. But I strongly second your basic theme that the only way to know for sure is to compare two identical cables or components in the same system at the same time, with one of them having been broken in, and one not.

I would further emphasize and/or add a couple of thoughts:

1)In addition to the possibility of user acclimatization, and the vagaries of aural recollection, it seems highly expectable to me that over the course of 300 hours of use sonically significant changes will occur that are unrelated to the cable or component being assessed. Aging or ongoing breakin of other system components, changes in AC line voltage and AC noise conditions, changes in RFI/EMI conditions, record wear due to repeated use, even seasonally-related changes in room temperature (temperature being a parameter that is fundamental to the physics of transistors and other semiconductors, for one thing). Again, as you indicated, the only way to rule out those kinds of possibilities is by direct comparison between identical items that are at different states of breakin.

2)I would expand your disclaimer about speakers being a special case, to which your article doesn't necessarily apply, to include all transducers (i.e., speakers, headphones, and phono cartridges), and also tubes.

As a point of interest, the most notable, extreme, and repeatable example of breakin that I have experienced is with my Stax electrostatic headphones. If they are not used for a period of a few weeks, which happens occasionally, there will be a day-and-night deterioration of their sound quality, that is instantly recognizable on most music. It can be corrected by having them play highly compressed rock music for a couple of hours, at volume levels that are higher than I would dare use if the headphones were on my head. That has been a consistent and repeatable phenomenon throughout the 25 years or so since I purchased them new.

Regards,
-- Al

Break in is real.

No way to determine reliably.

You have to let things run their course naturally.

Not good news for those looking to do quick, spot reviews of gear which is just another reason why all of those must be taken with a grain of salt.

Almarg - It isn't just your Stax headphones. A few years ago, I was forced for housing reasons to not listen to music for a year. My wife & I get to our new house and I set up my mid-fi Paradigm speakers - which haven't been played for a year -- and within an hour concluded that they sounded terrible and were done and needed to be replaced. After a few days of sporadic use, they regained their rich and pleasing - if undetailled - sound.

My conclusion is that break-in doesn't just apply to new equipment, but potentially to any gear that was left lying around for a while.

Break in is real. Trust your ears. As for manufacturer claims, I've heard from enough that it can take a couple hundred hours for a component, wire, or even just a chip to break in.

The actual changes I've heard were not so subtle, but across the board incremental (not the mathematically small type) so as to make me stop and take notice and appreciate.

It was never a big deal for me as I've witnessed this all through my being involved in this hobby.

As for my ears growing accustomed to the device at hand. Phooeey. Something that was bad to begin with, and broke in through time, still sounded bad and just had to go to the wayside.

Additionally, I've grown to accept something more dynamic, or detailed, or organic sounding that I didn't have before but that is not the same as getting used to something vs. it breaking in. One is a different presentation that would be audibly noticed by practically anyone and the other is something maturing, blooming or opening up as time passes. One is quite distinct from the other.

All the best,
Nonoise

Douglas_schroeder, "To date I have had no one, professional or amateur, contest my findings. I also have found no one who has replicated the test. I suggest those who doubt my little test, who ardently belive in Burn In, get double components and do the informal testing. I can tell you what will happen; you'll not be able to hear the difference. :)"

Well, apart from Geoffkait, I will also contest your findings.

However, before going into that, I will say that the phenomena of the listener "breaking in" to the component is just as real. I myself often notice this during parts analysis, which normally devolves into a mind numbing game of waiting. Our ears surely adapt to whatever's in front of us. I absolutely believe that explains a lot of why people live comfortably with their systems, only to have another listener come away mortified after spending time with it. As both you and Al stated, perhaps the most efficacious means toward countering this remains A/B testing.

The concept of break in parallels things like wearing in a new pair of leather shoes or blue jeans. There's a period where things undergo change; the before and after states behave differently in some sort of way(s).

A few quick anecdotes:
1) Working as a chemist / material science engineer during my 20s at a company that made high technology electronic materials, I performed many experiments on the conductor, resistor, and dielectric materials we produced for the likes of NHK, Vishay, Dale, Sfernice, Roederstein, Mallory, Panasonic, Sanyo, General Motors, etc. Proving the concept of break in to a degree orders of magnitude above irrefutable, the electrical characteristics of these materials do change in large measure during the early part of their lifetime, reaching a plateau of stable operation over what's normally/hopefully a long time prior to entering their phase of age or environmental related degradation

2) A definitive objectivist, Bud Fried, who normally spent about a third of the year in Europe, and influenced a fair amount of the work at companies like Audax, Dynaudio, Focal, Kef, and ScanSpeak from the 1960s through 1990s often recounted the research and development that went on. Practical use of a new driver would produce measurable and sometimes significant change in characteristics such as Cms, Qms/Qts, and xMax

3) A friend of mine whose business is rebuilding loudspeaker drivers often tells me about how the suspension (both surround and spider) changes. He's more of the type who would never measure this sort of thing empirically, but the spider in particular offers a visual and tactile contrast one can discern

4) Some time ago, I found a coupling capacitor shootout on the web. While there are more than enough of these out there, what made this one interesting was something due to the same sort of break in argument among the folks contributing there. Perhaps to satisfy his own curiosity, the gentleman conducting the test decided to run a PC based plotting measurement on one of the caps before (new) and after some run in to see if anything along the lines of "break in" could be detected. He wound up more than surprised at the obvious degree of difference

5) To your specific challenge, I have built several DynaKit ST70 amplifiers. After completing the new unit and confirming the typical measurements, I'll replace one I've been using for a while in that system with the new amp. Though the parts are normally (though sometimes, they're not) exactly the same, the sonic differences are always both obvious and predictable. It takes a good three to four weeks of playing most days for at least a few hours for the new amplifier to catch up to an older one. The same is true, though to a lesser extent both in terms of time and sonics when I go about evaluating parts like resistors and coupling capacitors in an already established unit.

The subject of break in tracks much like cabling. Even today I meet so many audiophiles who maintain that "wire's just wire." I begrudge them not. Likewise, should you continue to go forth feeling that same way about break-in, I understand.