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

Georgelofi wrote,

In response to this, "burn in" and "being out of adjustment" are not the same.

If you know better convince Nelson Pass of this below, in case you missed it.

Nelson Pass:

"We burn products in for two reasons -

1. We want to see if anything fails.

2. We want to readjust the amplifier against any drift in performance that comes with a burn-in."

Nelson Pass on "Burn In"
"It’s pretty clear that any such long term behavior is going to be
obscured by the burn-in of the listener. People come to new
audio components carrying the experience of the previous
equipment, and may experience some dissonance with the new
sonic character, even if they like it overall. Over time they often
get used to it and grow to like it.
There are plenty of cases where they initially like it, but the sound
becomes irritating over time. That is called burn-out."

Classic case of Appeal to Authority. I.e., just because someone deemed to be an authority offers an opinion on something doesn’t necessarily mean it’s true. One actually doesn’t have to look too far to find a designer of audiophile amplifiers or whatever who has stated he has some sort of issue with break-in/burn-in of amplifiers, cables, capacitors, wiring, fuses, wire/fuse/cable directionality, polarity, or anything else related to audio. In fact, if I may be so bold, amplifier designers might be the most dogmatic of the bunch. No offense to Mr. Pass or anyone else.

It's the massive teflon capacitors that need the break-in time.  I have a ARC Ref 10 preamp and I know it can be an agonizing process to wait for the full blume and potential, but as others have said its well worth the wait.  I can honestly say, having listened to and owned many other preamps, the ARC Ref 10 is the best I've heard (after 600 - 650 hrs of break-in).  It's within a hair of the VAC Statement that costs over twice as much as the Ref 10.  Hang in there your patinece will be rewarded. 
Ray

Excellent advice- Ray (rspyder).
Happy Listening!

Nelson Pass IS an Authority.  But he is simply stating what numerous experiments by cognitive scientists have shown.

But ARC made their amp and can advise you best -- even if listener subjectivity is an effect, that does not rule out teflon caps needing some time.

Also, as ARC how long they listened to your unit - they listen to every unit they make not just a sampling.

randy-11
Nelson Pass IS an Authority

Exactly! That’s why it’s an illogical argument. An argument cannot be won by simply claiming to be an expert in the field. Besides, amplifier designers disagree on many things. I'm quite sure I can come up with another terrific amp designer who disagree with Pass.