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.
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?