Break In Question?

Break in is real and not all can hear it.  Not all of us have the same ability to discern differences.  Even a great deal of experience and diligence can’t fully erase our real physical/mental differences human to human. That simple.  
 

I am a super-taster as confirmed by testing.  I can taste differences in food/product formulations better, far better, than most.  Born this way and experience/learning has helped.  But, I was born with a good measure of this “ability”.  Same principle applies to hearing and the other senses.   Some of it can be learned, but how each of us is created also plays a big role as we are not all the same. So if someone cannot hear this or that sound difference, then understand that is reality and there is really no reason to say it is the same reality for all others.  Take it up with our Lord and creator.  
 

No, I cannot taste the difference between a red and brown M&M. 🤓

@douglas_schroeder My brain has been brainstorming. What I’ve come to realize is your assessments naturally lead to very illogical conclusions. All of which pose more questions than answers.

All of the points below are of the assumptions the system sound is static and the change is only the ears playing tricks.

1) Why do some components sound different with burn-in and only with new products.

2) Why does the burn-in vary so much from almost 0 to even 500 hours.

3) If the ears perceive changes that aren’t really there, why does it only happen with new components.

4) If amplifiers warm up is false, why does it always sound virtually near its best at 90-120 mins mark. 

5) If the ears perceive changes, why does it not perceive change in your direct comparison. This sounds more like your ears are unable to differentiate direct comparisons. 

6) If our ears perceive changes that don’t exist, why do established system sounds identical every time? In other words, why do our ears detect no changes when there is in fact no changes, like a system that we 

7) I know exactly what my amp sounds like when it’s cool vs when it’s warm. Why does my amp sound its best after 2 hours warmup time, regardless of how long I’ve sat down and listened? The amp warmup sound is completely independent from my listening duration. 

@grannyring Yes, listening is a skill and it is indeed quite a skill. 

Plenty of people cannot tell the difference between 120hz and 144hz, but the difference is indeed there. 

@douglas_schroeder You admitted your beliefs tend to change over the years. But you choose to die on the hill where you fully relied on your hearing when it's at its weakest.

I got a new solid-state DAC that was gaining traction in the pro market but not in the home market. I was one of the first home users to buy this DAC. I met the designer of the DAC at a meetup and told him the DAC sounded fatiguing at first and needed about 150 hours on it to sound good. It has a feature to add 2nd order harmonic distortion to "tube it up" a bit. I told the designer I could not listen to the DAC without the 2HD cranked up at first. He was a little horrified at that statement since he discourages using that feature, except for edge cases.

After 150 hours on this DAC, I dropped the 2HD level to a very low number. Now with 1000+ hours on it the 2HD is turned off and the DAC is running ’naked’ as the designer suggests on his web site. However, one difference is that he now burns in the DAC for 150 hours before shipping. I had 2 brand new units to try this with and both had the same result.

A more well know home user DAC which I also love is the Meitner MA3i. I also had 2 of these in the house at separate times. The RJ45 Ethernet input on the MA3i is excruciating to listen to under 50 hours, after 100 it sounds very good. The USB was good right from the start. 

Let your ears be the judge.

@ozzy  I do not turn on my amp when burning in a preamp + DAC. With my latest DAC it does direct to amp, so I hooked it up to a Class D amp to burn it in.