And that’s of course just fine and interesting too, but if you think it sounds better it still does not tell us if something burned in or you got used to a subtle change and your subconscious wants you to like it.
Everything I said about the perceived improvement of my 300 was honest as well, and I also had a similar moment as someone else related, when during listening it suddenly seemed to “open up” in a big way. I assume most other forumers relating such stories are honest as well. This does not get us closer to the answer to the question “myth or not”, though.
Personally I think burn in is a reality, be it ps, amps, speakers, cables or switch.
Generally, when I buy a new component, I listen to it after 30mn, then let it burn in during 50 hours, 24/24, without listening to my system. So no brain fooling or bias.
My second listening is after 50 hours, then no listening between 50 and 100 hours.
In each case, the biggest difference is between 30 mn and 50 hours. For me it’s an evidence.
I suppose I’m primarily intrigued to know myself and share my findings with anybody who is interested. However I am a long way down the Naim food chain to consider myself an expert.
I have no quarrel with either of your statements in post 29:
“I’ve known electrolytic capacitors change their characteristics measurably after sitting on a shelf for a while. Connecting them to an AC supply for a while brought them back to what I was expecting”.
“I’m not saying they would affect sonic performance noticeably.”
How long might it take for an AC supply to bring capacitors back to their expected state? Perhaps half an hour, rather than dozens or hundreds of hours?
But then, there are so many other variables (not least the limitations of audio memory) over a period of 50 hours that could influence your perception of sound quality.
I don’t know about you but I often do multiple upgrades at the same time. I can always hear a difference but I’m damned if I know what component did what. I get confused and end up just listening to the music.
I am absolutely certain that capacitors have an end of lifetime & will need to be replaced. However, that is not the issue here.
What I am asserting is that capacitors do not need to be left permanently switched on in order for them to ‘sound’ at their best. Furthermore, leaving them switched on permanently will very significantly reduce their worthwhile lifetime.
…this experiment is still not valid: the components will not be absolutely identical. No way around this…the solution is to use the best measuring devices that we have, our ears (and neural pathway/auditory cortex).
What I am asserting is that capacitors do not need to be left permanently switched on in order for them to ‘sound’ at their best.
You are asserting, other people are asserting, gets us nowhere
Furthermore, leaving them switched on permanently will very significantly reduce their worthwhile lifetime.
Is this so? I have no idea. They will age in any case, is it worse leaving them off for ten years in a box or having them turned on the whole time? I don’t know but would like to. Decades ago I once read in a hifi mag that keeping them on prevents premature aging - this may have been wrong or not. Any facts appreciated
Edit: In computing for example it is commonly accepted that the changes and strains by turning stuff on and off all the time makes it fail faster
Not absolutely identical, but you could take two new 552s, for instance, listen to them, and if you cannot distinguish them turn one off and listen only to the other for 200 hours, then compare again. Given the significant changes that are frequently experienced, this should be valid enough
Edit: And you could be using electrical measurement devices and ears/cortex
Sorry - my use of the word ‘asserting’ was flawed. I really didn’t mean to be as “assertive” as that. Substituting the word “postulating” instead would be closer to what I had intended.
Incidentally, I used to leave my previous pre-amp and mono-blocks powered on 24/7. However, I am now abiding by the advice given to me directly by the designer of my current amplifiers that leaving the amps switched on 24/7 would significantly reduce their optimum lifetime.
I have experimented and came to the conclusion that leaving them on permanently gave no audible benefit (as far as my ears can tell). I now switch them on 30 minutes or so before a listening session, as per the recommendation of the designer.
Thanks. I will get around to doing this and it will be interesting. All of my kit (except 300 and speakers) is new, so I am currently leaving it on because I want as few variables as possible.
Of course, now we have two designers disagreeing regarding the SQ, and yours adding the recommendation regarding lifetime (but apparently also without specifics) while Naim says nothing about the latter that I know of - there are many imaginable reasons. Does your manufacturer offer/recommend servicing/recapping? And do they have a view about “run-in”?
Would be interesting to know what the capacitor manufacturers say.
Nice idea…but, on the other hand, the changes over the burn in period are so obvious that seeking objective proof is not really required … particularly in a domain in which everything, such as musicality, is so subjective. In my opinion that is.
Electrolytic caps age by essentially drying out. Accelerated by heat. Yes, its the heat that kills then rather than being left on. They degrade, slowly, whist being on a shelf not fitted. Many have manufactured dates on them.
But this has little to do with burn in. More to do with the main ingredient in a service. But like most things, they live longer if you keep them cool.
Agreed - though please note in my first post in this thread I acknowledged that electronics may change, albeit I suspect not as much as sometimes suggested, and I suspect up/down behaviour in that time is nothing to do with ‘burning in’. It would of course be easy to do the same comparison (blind) with cables…
That is what I have done for many years, simply allowing the electronics to reach operating temperature - though tge power amp will heat up a bit more in use unlike when I used an amp heavily biased into class A).
