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

"A skeptical open mind is always a good thing."

Interesting how a skeptical mind is often at odds with the open mind, no?

 
dchang1981
just show measurements that demonstrate a change after burn in then i'll be a believer.

How do you measure soundstage, grain, bloom and warmth?

Actually, an expert in court provides expert opinion or evidence, not proof. See the difference? Besides an expert can be wrong, his testimony doesn’t guarantee success for whomever he is testifying. And experts don’t always agree. That’s why the defense expert witness often disagrees with the plaintiff expert witness. Hel-loo! That’s why the Appeal to Authority is an illogical argument.

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.

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.

"I have yet to hear a tube amp that sounds as good after 5 minutes than it does after 1 hour let alone 4 hours."

agree. Air, bloom and soundstage are MIA until later on, after an hour for sure. This is the sort of thing that apparently separates the mid fi troops from the rest of us.

It might be best to take a deep breath and not worry excessively over break-in of components or cables, or speakers since most audiophiles are constantly upgrading or modding something or another. So the chances that anyone can actually determine how long a particular thing has completely broken in or ne able to track a particular thing's progress over 200 hours of playing music is rather remote IMHO given that the system is exhibiting constantly changing sound quality, both better SQ and worse SQ.

Even if someone is patient enough to hang in there for 200 hours or 600 hours, which I’m definitely not, the system sound can change for other reasons that break-in, external reasons like time of day, day of week, weather, or changes to the system, errors in the system, changes to house AC, etc. having said all that I am confident that it’s not expectation bias that explains why breaking in components, speakers cables and interconnects with the XLO Test CD break-in track played continuously for at least a few days, preferably two weeks, goes a long way to breaking them in.

Bob Crump used the MOBIE (Maximum Overdrive Break-in Equipment) break-in device on his TG Audio cables and interconnects for a number of weeks prior to shipping. I also used BOTH the MOBIE and TG Audio cables, which were spectacular by the way.

Georgelowbrow wrote,

"You and geoffkait need to get together and write a book on hifi voodoo."

All you need to know is that a sufficiently advanced technology is indistinguishable from voodoo.