Burn-in time Vs. Getting used to a sound


I have had much in the way of high end audio over the years. ...and the idea of an electronic item needing several hundred hours of use before sounding their best..is an accepted idea now (for the most part). Recently I have heard a growing thought of this just being the user getting used to the sound of a product.. Truthfully in the early days of Large Advents, DQ-10 Dahlquists and other gear..there was never any talk of burn-in time... Any thoughts out there on this.... Truth or Hype?
whatjd
To me , and this is simply an opinion , but anyone who does not believe that components need to break in either cant hear or have not heard a properly set up system , learned its sonics and tested a well designed component and observed its changes over time. Cases in point. I recently upgraded to the Conrad johnson Act 2 . It replaced a seasoned CJ LS 17 2. At first it was sonically inferior to the 17 . The company specifically issues instructions that at least 100 hours are needed for the teflon caps to sound acceptable and after 300, the unit is broken in . It was as accurate of a time frame as i could have imagined and i logged the real playing time as proof. I also purchased Pure Note paragon IC s. There is a 30 day return policy. The company told me that a minimum of 200 hours break in is needed before they open up. I started a thread on this issue 2 weeks ago. They have dramatically altered their sonic signature and improved in virtually every aspect of its performance. This but 2 examples . Dont get me staretd on the aerial 20 t break in period where i was committed to an insane asylum before they broke in and became magical.. Breakin is a myth ... spare me. But .... thats my opinion.
I think it is a combination of both, actual physical change to the component, and the listener becoming use to the particular sound of the component. For speakers and phono cartridges, mechanical movement will loosen things up and the change is very evident. I am not so sure with cables. For electronics, I've heard pretty big changes with some components. I've gone through the turn-on, turn-off routine recommended to burn-in a new Naim CDS3 CD player, but I can't say that that sped up the process, although it is clear that the CDS3 changed over time.

But, not only is "burn in" an issue with new components, even older components that have been turned off for as little as a few hours can take a long time to come up to song. For example, there is a reason why Naim gear is designed to stay on at all times -- it sounds horrible for a whole day after a prolonged shutdown. The explanation I've heard is that it takes quite a while for the power supply capacitors to fully charge and physically regain the form they take when charged. Fortunately for me, tube amps take only about 15 minutes to warm up.

Electrostatic headphones also take some time for the diaphragm to fully charge and will sound thin and brittle until that happens. My Stax Omega IIs take at least 10 minutes to become even listenable.
It's funny how after burn-in everything always sounds better. I've never heard someone say; "After a complete and long burn-in the [component name here] sounded like crap." I fully believe that complex electrical components need some run-in time to stabilize but as an audiophile I remain skeptical on all "known" issues and let my ears be the judge. I've never had an overly bright interconnect cable turn into silky joy after burn-in.

Thanx,
Russ