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

Studies by cognitive psychologists show that sensory experience alters perception.

So, is it the tubes, the caps, or the listener?

They use tubes.

As to how long why not contact ARC?

BTW, they listen to every unit before it leaves the factory - and I think a single person still does all the final listening - yet another guy named Wendell from a high end audio co. in Minnesota - what's in the water over there??

the only breakin time I worry about is with new speakers

I do think ARC tells you to warm their components up a bit for best sound, but it won't kill you to listen to an ARC pre-amp that isn't all the way warmed up


at least, it won't kill you right away

I’ll add transformers to my above post...

tho I have seen reviewers say the teflon caps.

The real question is what ARC says...

Anyway just leave the system on with a CD on repeat or something while you run errands, etc.

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.

what was the insult darkmtter?

No one can deny that Nelson Pass is an expert, and the experiments prove him right.

Or are you a science denier?

Authority is not as good as an on point experiment but a LOT better than an ill informed opinion?  If you don't believe that then do your own surgeries and find out.

anybody can build their own gear

anybody can read a textbook on cognitive psychology too (well, ok not everybody...)

I agree it would be hard to measure a change - tho one could arrange a blind listening test to show an effect w/o knowing any mechanistic reason for the effect
but...
if ARC says to do something, why not do it?

for my ARC pre-amp it warms up for about 40 seconds - could be tube protection tho, not SQ