Burn-in Questions

[wilberforce]

Well, I just became an official Bottlehead today with my new Stereomour amp. (Yay!)

I've been reading the forums here, and see lots of posts about burn-in such as, "Ive got about 200 hours now on the JJ 2A3s, and they're really starting to..."

How do you guys keep track of the hours you're putting on your gear? Do you keep a log? Are you guess-timating? Is there an electrical meter you can plug the amp into that records hours?

Do tubes and caps burn-in without any music playing? Do you just leave the amp on for long periods? What about playing music at low levels?

Of course, some people think that burn-in is nonsense. I definitely think it's a real thing with certain speakers, the drivers being mechanical and all. I can understand why tubes have burn-in periods, but why do caps?

[JC]

First off, congratulations!

As to burn-in, I always just play the amp like I would any equipment.  So, no, I don't keep track of the hours in any way in particular, other than maybe a calendar.  

If you are interested in hearing the differences as it burns in, play a piece you are very familiar with, then put it away for awhile.  Bring it back out after you reckon that the amp as been used for a number of hours, then play it again.

I certainly do not pretend to know the mechanism(s) at work here, but I can say that I have experienced the changes; I recall one set of output caps that sounded good at first, then went through a stage where they were so bad that I almost yanked them, before they settled in to sounding just remarkably good, and they sound great to this day.

As a rule, about 50 operating hours (playing music) seems to be the point where most of the amp gets burned in.  There are many exceptions, of course, with some parts taking much longer.

[Grainger49]

We all SWAG the number of hours.  (Scientific Wild Assed Guess)

[wilberforce]

We all SWAG the number of hours.  (Scientific Wild Assed Guess)

Excellent! That fits right in with my style!

[Paul Joppa]

Sometimes called "Proof by Atmospheric Extraction" among my engineer friends.

[SteveH]

When we're estimating engineering jobs at my company, we tend to use a 'ROMA', as in Right Outta My A$$...

Management hates that!

Steve

[Doc B.]

The exact amount of time it takes to completely break in an amp is the amount that passes before you stop saying "wow, the sound is changing as it continues to burn in."

[Grainger49]

Doc has a good measure you go from "WOW!" to "MMMMmmmmm...."

[ssssly]

Seeing as I compulsively change components just to see what they sound like. I've always likened it to how many licks it takes to get to the center of a tootsie roll pop.

I generally consider an amp, with components in it that I familiar with, burned in when I stop listening to the amp and just start enjoying the music. If that makes any sense.

[wilberforce]

I did notice a change in the sound last night. I had let it run all day long at low levels in the background, but when I cranked it, it seemed as though there were more highs, almost too much--in fact, I got up and turned down the L-pads on my speakers a bit.

[ebag4]

I guess I am a bit more anal than most.  I built a spreadsheet that totals the hours on the amp as well as the hours on each of the tube changes and mods I have made.  I used to do a total by hand but this simplifies things.  Not that I am totally anal about this, I do round off in 15 minute blocks.  ;-)

I will only do this until I have 250-300 hours on everything.

Here is a pic:
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.hawthorneaudio.com%2Fphotos%2Falbums%2Fuserpics%2F10060%2Fspreasdsheet.JPG&hash=673cdb84a744d14663c0d05c6d10e77f50cff6b9)

I used military time (sort of) with the hours in 1-24 format but the minutes are input in 15 minute segments (e.g. 23.25 is 11:15, 22.50 is 10:30 and so on).  I did it this way because I had an issue getting time to convert to a number of hours.  I am sure it is easily done but I didn't have time to research it.

Best,
Ed

[wilberforce]

Interesting. I could never get that organized--I drink too much. 

What I'm doing initially since my Stereomour came to life last Sunday is to run it about 10 hours a day, mostly at background levels for the neighbors and my ear's sakes. After awhile, I don't think I'm going to worry about it.

It seems to be settling in. Last night my daughter came over to hear it, and it was sounding magnificent. I let it run full out on the Telarc recording of Stravinsky's Rite of Spring, and it was terrifyingly massive, but so clean. She was amazed at the difference in sound between the Stereomour and the Sherwood that used to drive the speakers. The Sherwood sits idle, unconnected, in a jealous rage. It's a great sounding amp, but the SET amp is something altogether different. I'll put the Sherwood to use with my JBL 4311s, they get along very well.

[Paul Joppa]

Do you keep track of the time there is music, and how loud it is?  :^)  Seriously, caps seem to need signal as well as operating voltage to break in; tubes seem to need just time operating.

[ebag4]

Do you keep track of the time there is music, and how loud it is?  :^)  Seriously, caps seem to need signal as well as operating voltage to break in; tubes seem to need just time operating.

Hi Paul, if this is directed at me the times used on the spreadsheet all reflect time actually playing music, however the volumes vary.

Edit, just saw the smilely, you were probably just ribbing me, yes, a bit anal, I know. ;-D

Best,
Ed