break-in--bane or boon ??

Mrtennis, "so i allow 300 hours, as a standard practice."

Given the factors in play, it sounds like the wisest strategy.

I'm afraid thing are even worse than we might assume since active burn in devices and burn in tracks on some Test CDs will further improve cables that have been in the system for many years. Infuriating' ain't it?

GK

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.