Burning-in as a non-linear experience

With speakers and headphones, this has not been my experience; they tend to start off sounding pretty bad, like the various components of the speaker had never met each other, and as weeks go by, they blend together and the speaker sounds like it should after a couple of months. 

Burn in seems to normally be non-linear and varies between components.

A while back I had the experience of breaking in three identical Audio Research Reference 160s amps, without changing anything else in my system. I was very shocked how each went through exactly the same sequence… approximately but not exactly the same as other ARC components.

In general the sequence was that out of the box they sounded a bit trebly and flat. They would gradually improve for about the first 100 hours. Sounding much better. Then wildly fluctuate between bad and good for about twenty or thirty hours. I mean, when I would turn it on, i never know of it was to be Jekyll or Hyde. Then it would settle down and improve slowly… not linearly but at a diminishing rate through 600 hours. What I was surprised is, while really small… there was a small amount of improvement through 1,000 hours and then rock steady.

I have lots of experience with other components as well. But this tends to be how ARC has been in the last twenty years.

On a related issue. Warm up on the Audio Reseach Reference 5 preamps was very unique. Just turning them on was not enough to get the best sound. A signal running through it was required. It was really obvious. You could turn it on for an hour and then sit down and listen to music. The first ten minutes it did not sound that great… and then over about ten seconds the sound quality would improve significantly. It was really obvious and at times seemed to happen over a couple seconds. I thought I had to be imagining this… I had never heard anything like it. I went to a high end forum and I couldn’t believe it. There was a thread about this exact phenomenon.

Reference 6 do not do this, in fact the warm up effect is very small. In general it sounds great as soon as turned on… meaning I hardly ever notice the difference. There is a small difference after ten minutes, but it is very small.

I am doing this currently .i have rebuilt many Loudspeakers 

Xovets and ftiver breakin ,and Xovers much more so is very real 

The metals have to stabalize, the dielectrics 

Much more so  teflon can tske hundreds of hours .

Capacitors go through changes. Bright when  new.

Then sometimed dull then forming stability

Its bern proven many times. This applied to everything.

Digital daid by mamy companies hundreds of hours for 

It is a very low voltage  and takes time.

I agree that sound quality improvements during burn in are not strictly linear.  There are multiple regression periods where there is linear, exponential, and stepped improvements as well as plateaus.   My experience has shown the improvement model and extent of improvement varied with each piece of equipment.  However, I have never experienced periods of negative regression (decreasing SQ).  The regression over time was always positive (increasing SQ).  I had a previous Krell amplifier recapped by Krell twice.  I considered the burn in process normal where SQ improvements began to level off around 300 hours and plateaued at around 500 hours of burn-in.  I do not know if you consider that extensive.  Remember, that is only my experience with my amplifier and the CAPS from the OEM.