Why does it take so many hours to brea in arc preamps and amps?


I recently purchased a like new ARC 5 SE pre amp.  The unit had less than 200 hours on it.  Everything I have read states that ARC preamps take up to 600 hours to fully break in.  Why is this so and what improvements can I expect to hear as the unit accrues hours?
ewah
Again, I'm not sure where you are getting this info from.

" And your talking 600hrs for each change in the prototype.
Any further changes made to the unit under development, gets broken in before the changes are evaluated."
600 hours? Where did I say that? I've never had an ARC product take that long to break in.

" From this, as it infers that it’s in prototype stage. When a product is finalized there are no changes to be made once in production, as it’s all sorted. "

You're stating the obvious. Besides, I already addressed that in my last post. The last prototype is the production model.

Since you want to go back to my "where did you get this info from" question, you're conveniently leaving out the portion of my post that's most relavent to the question.

" And the way your inferring is that the production ones are deliberately out of adjustment/calibration to factor in "break-in" period, which after those adjustment/calibrations are magically back in spec?? I think not. "

Show me where you got that from.

" To all those that say the manufacture has specified a certain "break-in" period, please link the rest of us to those manufacturers links, instead of it being just personal opinion. "

I just noticed that.

Ayre

Due to the manufacturing processes used for the wires, capacitors, and circuit board materials, a break-in period is necessary for the amplifier to reach its full sonic potential. 100 to 500 hours of music played through the system will ensure full break-in.

Theta

Getting to know your Dreadnaught D This Dreadnaught D has been put through a rigorous and unique testing procedure that ensures that it will last for many years with minimal service requirements. This procedure includes the following: •All assembled circuit boards are given a thorough visual inspection and are then tested in a bench-reference Dreadnaught D. •The tested, assembled circuit boards are then installed in a new Dreadnaught D and the whole unit is tested for every function and parameter. •The unit is put on a burn-in torture rack to test for any possible component failures. •It is then tested on an audio analyzer for all pertinent parameters. •The unit has all remaining chassis components installed and then undergoes a complete visual inspection, which assures that all Dreadnaught D’s meet visual specifications. •The Dreadnaught D then undergoes a critical listening and functional test. Burn-In Time While the Dreadnaught D amplifier will sound wonderful without any burn-in time, users may experience small sonic improvements during the first week or so of operation.

Burn-In/Break-In Time This unit has a break in period of about 1 week during which continuous improvement in sound quality will be observed. It is recommended that music be played continuously through the unit during this time to expedite the break in period.

Aesthetix

BURN IN TIME This unit has a break in period of about 1 month during which continuous improvement in sound quality will be observed.

There's 3 examples. If you want more just read an owners manual. Also, when you read through the Theta example, the break in requirements are different for Class D amp than traditional AB.

This to break-in or not break-in question pops up regularly regardless of the "object" in question; internal combustion engines, tires, etc. And there are always folks who argue against or for it. While there's some truth in the notion of the "expectation bias", there's no denial that physical (or chemical) properties of most electronic components changes as a result of going through constant temperature cycling. Some get better some get worse, depending on the piece in question. There is one fact that remains common - the longer a component is left on, the lesser it will last.
"
a lie told many times becomes truth.

V Lenin. "

Not always. After 65+ years of Leningrad, the Russians still remembered the name of their city was St. Petersburg.
rsv4, one lie is too many and there are many. some lies will and some won't be remembered and that's where the trick is.
While the Dreadnaught D amplifier will sound wonderful without any burn-in time, users "MAY" experience small sonic improvements during the first week or so of operation.
"MAY" this is a get out of jail card. Otherwise they would have used the word "WILL" 
It also infers "Expectation Bias"

The unit is put on a burn-in torture rack to test for any possible component failures
This test is for weak/faulty components under heat stress, not to "burn in" for better sound.


Cheers George